The differences between the generations are not necessarily an upgrade or improvement if one is happy with the Gen3; that's an option that will still be available. If you like the different grip, interchangeable back straps, larger mag release, and an extra mag, then you've answered your own question.
The only reliability issue that I've heard of has been addressed with a new recoil spring for the 9mm models, and this issue has been addressed by Glock.
Short of being a "me too" post, I've not had any issues with my Gen4 G27. I don't have a good round count, but I've likely put 1000+ rounds down range since I got it last spring. I've also not experienced the FTRB with my Gen3 G30sf that so many were up in arms over (pardon the pun); many, many rounds through that one as well.
IF you like the design of the Gen4, get it; if you're nostalgic for Gen3, you'll not go wrong with it, either.
The only reliability issue that I've heard of has been addressed with a new recoil spring for the 9mm models, and this issue has been addressed by Glock.
Short of being a "me too" post, I've not had any issues with my Gen4 G27. I don't have a good round count, but I've likely put 1000+ rounds down range since I got it last spring. I've also not experienced the FTRB with my Gen3 G30sf that so many were up in arms over (pardon the pun); many, many rounds through that one as well.
IF you like the design of the Gen4, get it; if you're nostalgic for Gen3, you'll not go wrong with it, either.