In short- it is awesome. Feels great, shoots great, looks great. One of the best out-of-box triggers money can buy. I went through 5 handguns trying to find the right one (for me) before I discovered the PPQ. Haven't looked back
Edit - also welcome to INGO, fellow Greenfieldian!
Fantastic handgun! My M2 is the least expensive handgun I own and one of, if not, the best. I don't know about the M1, but being an original HK fan and familiar with the paddles, I think that the M1 makes a lot of sense. Get one! I own MANY handguns, FN, Wilson, HK, Glock, CZ (newly acquired), and the Walther holds its own.
I'm trying to think of an auto loader pistol I own that doesn't have a reversible mag release.
And I can't. Unless you count a European release. Which sucks equally for everyone.
I like the mag release on that pistol.
But I wouldn't choose it because it's the only "lefty" option.
In my opinion the Walther PPQ is the polymer gun right now. At least out of the box. Glock and M&P still have the leg up in aftermarket support and accessories. Only real weakness in the PPQ is the good but plastic sights. M2 has a reversible magazine release and is lefty friendly.
It's an awesome gun in every way. The trigger is what sold me.
I have bought and ended up selling several guns over the years after finding something I liked better, but this one is a keeper.
They have another weakness besides the plastic sights... the very front picattiny rail stop is too small and weak. Mine broke off while using a flashlight. I just got my PPQ .40 M1 back from Walther. Warranty service was great but they had to swap out the entire gun. They advised against using a Streamlight on the gun. I have three Streamlights & I'm not switching lights. I put the light on my HK VP9 instead and now wonder if I should sell the PPQ or not.
I love mine. I have to echo everything everyone else has said about theirs. My wife and I have consecutive s/n 4" 9mm m2's. Dad has the same, except his is an m1. My buddy and his brother have a glock 19 and ppq m2 4" 9mm, respectively. The one with the Glock is regretting his decision after trying the PPQ. As far as the rail goes, that is the first I've heard of it. Dad mounted a viridian light/laser on his and has no problems at all.
On the + side... my old P99 .40 12 round mags work fine (red followers) and the gun fits into a Safariland ALS holster just fine too. I swapped in some nice metal Dawson night sights. Those are file to fit and weren't very hard to install.
I like it, just don't use that very front rail slot to mount heavy accessories.
I looked very seriously at the PPQ vs. the HK VP9, and it was a hard decision. I loved both guns! In the end I went with the VP9, but not because there were any issues with the PPQ.
I personally like the mag eject paddles on each side of the trigger guard now that I am used to them. It took a while, but they are actually pretty intuitive.