I wouldn't mind doing some spreadsheet magic to evaluate how much AR/DR gain or loss is required in armor vs gun matchups, but that sorta work is usually done by theorycrafter optimizer types, and I am sure no one wants someone like THAT around.
But for real, as part of trying to do some charop for 6e I DID look into how often it matters DR differences matter. Its... really not often. You gotta remember that for an AR or DR gain or loss to matter, it needs to swing the calculation by more than 4 in the direction it is going, or get you to within 4 if you aren't already. Defense rating from armor caps out at +7 if your in full body armor, but will be +4 on most NPCs ready for a fight. Body generally ranges from 1-6, but can go as high as 9 on a troll optimizing it.
This means DR ranges, without augs, from 5 to 16, realistically concentrating at around 7. Most NPC statlines back this up, but it can get as high as 18 in niche situations.
Most rifles are 'inside' this already in their optimal range, and are so far outside of those scores in their sub-optimal range that even a +5 bonus wouldn't get you inside the top end vs the best NPC statline DRs. For a more average DR, the 'mid tier' ranges still are inside and are solidly inside (its 8 AR vs 7 DR, so you need to either swing defensively by 5, or offensively by 4, which is not super realistic). The same is true of shotguns, SMGs, and pistols. Basically once you get to 11 or 12 AR (Which is extremely easy, just slap a smartgun system on) your AR borderline doesn't matter in optimal range. It matters a bit in suboptimal range, but only vs the best opponents in the game. Firing a FN-HAR vs someone at point blank still doesn't swing edge either way as long as they have less than 9 DR, which is extremely likely, but if they had good DR like a SWAT officer you wouldn't really care if you somehow got +5 AR, you would still be giving up the edge.
It becomes intuitive why this is happening. Guns have a set AR for the most part by range, which is their base value +2 for a smartgun. Your armor value can be off by that by 3 and not matter, meaning there is a range of 7 numbers where you absolutely don't care if your AR changes for the better/worse relative to them. The direction may matter a bit, but because DR caps out at like... 18 on a non-troll if you absolutely optimize for it (Which NPCs tend not to do and PCs have better things to optimize for) you are extremely safe just evaluating weapons by range category, not AR and DR.
SR6 may have been better suited noting guns give away an edge at certain range categories, and gain ones at others, than AR and DR calculations. It seems the INTENT was the benefit of fighting in melee vs a long rifle is edge, but your actually probably not getting it unless your an out and out 'soak tank' build, as to beat out a rifle shot in hand to hand combat requires you to have, assuming your wearing an armored jacket, a combination of base DR and bonus DR of 6. So we are talking body 6, or body 4 with some serious investment into defensive augs, to make that happen.
So it does seem safe to say the conventional wisdom of 'you generally are better off not bothering' is true, at least with PCs on the offense. Defensively, because AR is a bit more 'set' than DR, you can plan around eating certain shots, but outside of melee range or longer ranges its so hard to get your DR to where you need it to start earning edge (you basically need 15-16, so 12-13 outside of armor to make it consistently happen) you probably are better off optimizing for things like full defense or offensive dice or... just starting with lots of edge in a fight.
Put another way: Does your table routinely fight NPCs with DRs of exactly 7, 9, 13, and 15?
If the answer is yes, then congrats, getting +1 AR on your Ares Predator that already has a smartgun would be a significantly consistent change in outcome for your attack rolls. 1, 2, 3, 4, 5, 6, 8, 10, 11, 12, 14, or anything 16 and up? Doesn't matter. No effect on the game what so ever. So ignoring the infinity after 16 (lets just count to 18, which is the highest 'grunt statline. It can go higher but realistically you can't push a pistol up that high to chase it anyway) that is 4 intergers where it matters, and 14 where it absolutely doesn't. Assuming DR ratings are randomly sorted (They aren't, they concentrate towards the range where you don't care, but lets not think about that for now), vs 20% of enemies that 1 point AR/DR shift matters.
Now I would probably spend a couple thousand nuyen and maybe .1 ess on a 20% change in outcome (assuming I am not over-generating edge already), hell that is often a better outcome than a reflex recorder on attack in SR5! So power level wise, maybe worth it. But it isn't a big deal from a tactics/system sense where it is worth a lot of focus, it ultimately is a lookup chart system to figure out how many modifiers you need to affect the outcome at all, with most of the time it being too many bonuses to obtain to be realistic, and certainly isn't worth a lot of systems biasing towards that.
It gets a little worse with the imageing scope though, which allows us to effectively ignore any situation where we don't have enough AR in many combat situations (it costs a take aim, but that is a useful combat action anyway we want to take!). This means the only numbers that matter are the 7 and the 9. The 9 only comes into play if we fire at medium range, and while medium is the larger category, lets be realistic and account for the fact you aren't going to need to fire past 50 meters that often, that is half a football field away and will vastly more often not matter. This means 1 integer out of 18 is relevant, so 5% of the time it affects the outcome, which is quite a bit worse than a reflex recorder on a 14 dice shooter in SR5.
Defensively its a bit weirder, because you can do more to affect your 'base' value, but you basically just need to be within 3 of the number 12 to always ensure you never give up edge. 3 armor and 4 body gets you to 7 (already in safety for most guns that aren't firing at optimal range or lack smartguns, but the odd short range SMG or rifle shot gets ya), and then you can get +2 and forget about it for the most part. Big breakpoints defensively are 7 (most guns hit at 10 in their optimal range if they aren't focused on mid range shooting but you can get unlucky, but its the cheapest get by far), 8 (and a lot of the best guns are both high DV AND have 11 AR, but that only protects you without smartguns), and 10 (For pretty much definitive safety from edge gains). You basically can't go BELOW 4 as a PC, due to armored jackets existing, and you probably have at least 6, which puts you out of range of most trash guns anyway. Its a little more complicated than figuring out where you try to park your AR, because unlike yourself NPCs aren't always using good guns and may go for some trash, and because there isn't as clear a way to get to 'total safety DR' unlike AR, but its not not very much, and I believe Firing Line's new armors already push you to the point where you can more easily get inside the safety range without lots of ess or atts points.
Basically? A huge problem of AR and DR which would be spotted by any optimizer/minmaxer in a heartbeat is that it has a very few number of breakpoints, or values where going past them doesn't generate a lot of value. Most breakpoints are fuzzy (For example, in D&D feature gains may slow down a bit making it a good time to hop off, but it isn't objectively worthless to go past the last monk breakpoint of 11. In SR6, it sorta... doesn't make any real sense to worry about AR gains unless new options come out that swing AR and DR a lot even on the same target so its harder to just go 'I am fine giving up an edge vs Red Sams and Swat teams because I can't realistically get +5 AR anyway... but that would make the system way worse than modifiers in terms of simplicity, it would be possibly one of the more complex combat resolutions in RPGs (Because now your both calculating modifiers AND applying them to two numbers to see if their relationship falls outside of a 7 integer range).
Once you sit down an start hammering it out, it sorta is.... clear it does nothing most of the time, and its the worst kind where it DOES sorta matter in very rare cases but you have almost no control over if it will or won't matter defensively and in a way that makes you spend resources for something that SHOULD be tactical or a consistent character aspect but most of the time it won't matter. It doesn't just not matter a ton (A LOT of things don't matter a ton) but actively creates feel bad moments all over the place, because in most fights your orthoskin does nothing and you paid your most precious resource to get it.
Edit: Actually its worse because an edge swing each attack isn't actually a change in outcome. It is a potential change in outcome. More math to come!