I use it. Cut my teeth on it, so I don't find anything awkward about it. I have well over 8700 rds of factory 147gr ammunition thru it, with two failure to feed. Once in NS, and once in NB. In both instances it was traced back to a really crappy mag that I would only use if I run out of mags on my belt,(the lips were all bent to crap, and I tried heating the plastic to remold it, but made it worse).
I like the mag release because I don't have to shift my grip to press the mag release, and I have to take my trigger finger out of the trigger guard to push the mag release (hence, my finger is out of the trigger guard to change mags, which should always happen when moving, when your finger should not be in the trigger guard)
It is reliable, reliable. The only thing I have changed are the sights, I have an ameriglo front sight (listed as the tactical), and a rear set of Mepro adjustables. I performed some trigger smoothing via light polishing/detailing as per instructions by Bruce Gray on the HKpro forums. This helped reduce the DA trigger, but more importantly helped smooth it out. The SA is very good. I use a Speedsec holster, but i would recommend the Dropped and offset Bladetech holster instead of the speedsec. I am picky, and if a gun doesn't work reliably, I don't want it. I have two HK usp 9mm's. One is a DAO LEM , and the other is a Variant #1 (TDA), but it will soon be a Variant #3 (no external Safety, not needed in Production, as you start in DA mode).
Mag changes are pretty easy with this gun, as is target aquisition, (front sight is huge) but no matter what you get, everything takes practice. I use 15rd mags (blocked of course), which have the finger extended base plate.