For Glocks in airsoft. This info is based on guns I own or have owned.
If you want the best airsoft Glock it is the KSC Glock 19. If you really want a Glock 17 though the TM is much newer, has a better hopup, easier to find here and has a crap load of aftermarket parts. The KSC Glock 17 was good though I just ended up liking the TM better.