The anniversary has some competitive advantage simply because its signature is flatter and the mids are more forward and detailed. The mids really aren't a focus on the X1, plus the bass can get distracting. Overall I think the advantage isn't huge though. The X1's soundstage is more open and spacious and the imaging is a little sharper, so it regains some lost points there. I don't blame the X1 for not being 10/10 competitive though, because I think they do a damn good job of pulling off the best competitive they can while still managing the fun signature that they do.
For me, it's the X1s for single player gaming and movies/TV. I'm using the Q701 right now for multiplayer gaming, partly because of it's lighter clearer signature, and partly because that type of gaming is more intense and I'm afraid of wearing out the X1 pads by using it for that. The Q701 pads are the easiest to clean/replace of the three types. I also usually pair the Q701 with my iCan and set the bass boost switch to
rape which adds back a lot of fun to the Q701.
For music it's sort of a three way split, but usually it's either the Anniversaries or X1s getting the head time, with the Q701 getting less. It depends on what genre I'm listening too though.
I really like them both though, and it would break my heart to sell one of them