I like the idea, the factory TR is definitely too high. And I always like seeing more aftermarket ps90 products out there.
The only drawback is it leaves the mag quite exposed. Personally I like how the factory ps90 receiver encloses the mag and offers a bit more protection in the event of a drop, fall, toss, twirl, etc that an elite operator like myself might subject it to
. IMO that's one of the drawbacks of the AR57 as well is how the mag is so exposed. I've even thought about devising some rail mounted mag cage for the front part of the AR57 (yet another project).