I own one. I don't know what the first reply is talking about, concerning the three itty dots. Mine has standard GLOCK sights, meaning 1 huge dot and a giant U.
I absolutely love the "air craft carrier landing deck" with the huge blocky GLOCK sights. Target acquisition is FAST. And the gun is very accurate and easy to shoot. Good groups are effortless and consistent. The recoil is tame, but the push does wear me out. My groups start to suffer after 30 shots or so, due to the relatively light weight of the gun. But I don't shoot very often.
I dig the ambi release. I always use the "wrong" button, because I can reach it without shifting my grip. But I do believe that it takes a bit more force to reliably seat the magazine with a closed slide than on the normal mag release variety GLOCKs.
I adore this gun, but it's too big for me to CCW regularly. And the limited holster selection does not help at all. This could be a big negative for the picatinny rail if you plan to CCW.
On the other hand, the big rail seems to balance the aesthetics of the large grip. It's a good looking GLOCK, if there is one.
Some of the early picatinny variety were made with a stock of rough trigger bars. Mine included. But a 25 cent trigger job fixed it.