I'll admit that when I play a character who focuses on Automatics, I typically grab a machine pistol (sometimes two), a SMG, and an Assault rifle. Multiple weapons gives you options. Options, IMO, are a Good Thingtm. Use the assault rifle for when you want to go loud and heavy, loaded up with as much RC as you can get. Use the SMG for times when you need power, but desire something that can more easily be hidden under your lined coat. Use the machine pistol (perhaps suppressed) when concealing it is your main concern, or as a backup for the others. A sling on the AR and SMG and a concealed holster on the MP make it so you can carry them all fairly easily.
Personally, I rarely used FA in 4th, and I don't expect I'll use it much in 5th, either. The main places I used FA were with drones (vehicle mounted weapons don't suffer recoil, so why not?) using an LMG. I've used suppressive fire maybe twice. And that's mainly because in my low-init characters, I typically take something like Longarms (for characters who used sniper rifles at a distance, and shotguns up close), and Pistols (for a Face).