We could talk about FR for ages but, beyond this question, the most important thing is that the mod makes the Q701 much more involving, fun and musical, thus making it a fantastic audiophile all-rounder.
I found the bass a little too loose the first few days, but not anymore (post-mod burn-in? LOL). Plus, I did the foam tweak, which takes 5 minutes and is 100% reversible.
Does the mod make some frequencies sound artificial? Not at all. IMO, it makes the Q701 more balanced and natural sounding.
It slightly changes the presentation though, a tad less intimate and forward (possibly due to a better imaging according to Tdock). But this is NOT a deal breaker.
I'm pretty sure I won't go back to the original Q701 (I would love to have both versions though).
Since it is easily reversible, I say "Just mod it!"
I'm kinda jealous that most of the users here are able to maintain this mod. For me, removing the sticker really did balance out the entire chart, but it was fatiguing to listen to. Is there something I can do to maintain this mod but reduce the fatigue?