Thank You so much. Very informative thread and helped me a lot I believe. I have not much experience with the Glock pistols, but currently looking for model 22. I'm planning to join the local LE agency in the future, so familiarizing myself with this pistol sounds like a good idea. I have a pretty good choice of the models - generation 2, generation 3, generation 3 RTF2 and generation 4.
I'm torn between generation 2 and 4 now

Don't like the finger grooves, but the newest models suppose to deal with the recoil better.
Anyway, again - your information is great and very helpful.
Thanks