I picked up my G30 SF (or so I believe it to be) yesterday from a local shop. I have been searching for a G30 for a long time and finally found one but the lady selling it didnt know anything about it and I believe it was mislabeled. They had it listed as a G30 but after searching the internet for the last 4 hours I believe it is a G30 SF. So my question to you guys is what are the differences between the G30 and G30 SF. I already know the one obvious difference is the grip but unfortunately I do not have another gun to compare it to. Are there other ways to tell by markings or other differences in parts? Also how can I tell if it is Gen 3 or 4? I know most Gen 4s have the double spring inside but then some people have been seeing that in the Gen 3s also. Any help is appreciated!