Glocks range 450-600. Accessories can cost you more i.e. tac lites, laser, grips, etc. There a lot out there. I have seen Glocks look like something out of StarTrek. The "C" models are you compesated ones. They do have a noticeable muzzle flash, even in the day time. I don't see the difference in the reduction of muzzle climb with the larger frames however. It is noticeable with the compact and sub-compact models. The triger group of the Glock, with the exception of the actual triger, is all metal. The slide and barrel is all metal. Only the frame is polymer.
Many will talk about the kB effect of Glocks, specially with the .40 S&W calibers. I have yet to experience this. Most of these were caused by hot reloads. Which Glock tells you not to do. These occassion are few but highly publicized much like gun violence in the media. I've had a Glock 22 for about 2yrs now and no kB to speak off. I have only used factory loads.
The action on a Glock is a take it or leave it proposition. The trigger, for me at least, is awesome. There is no play to it at all. constant pull and never get loose. I love. I suggest you shoot one before you buy it. Worse case scenario you can get a 3.5# triger installed.