I do think it's worth taking 1 sec to note this. Given the choice between forcing your opponent to re-roll a success vs you re-rolling a failure. The only worth while option there is forcing them to re-roll a success. You have 67% chance of them failing the re-roll vs 67% you wasted a point of edge on a re-roll. Now if conversion of a 4 to a 5 is an available choice for one edge that's a better then both those others, as you're looking at 100% chance of getting a success there.
So the whole equal odds canceling is not good, but it's clearly just isn't going to change these folks minds. To me the issue is under the Edge system, if your prep a position, and then enemy moves in. All you're going to get out of is a chance at a point of edge. When I say a chance what i mean is given how edge generation is capped, if you were already going to get 2 edge, then preparation and tactics will likely have no meaning. That's what I don't like. Building logic in 6e will dictate your character build to get 2 edge in any opposed roll scenario. Even if you don't really want to build that way, it seems like you won't have a choice. If you're using the best weapon and armor possible given availability and resources, odds are that's one edge then it's a question of ware. So once you're at 2 there is zero point in doing anything else for tactical advantage. You can of course show up in a bikini and packing plastic spork as your weapon of choice with the ware and then act tactically hopefully to get that 2nd edge.
And while the play test generated edge in each opposed roll, that won't hold in the live version. Making the system still less useful.