I've got an Adtech, and I gotta be honest, I don't like it. Personal preference, mind you, but I have to keep pulling the trigger constantly to get glue to flow in a long run. I have a Dewalt glue gun that i like better because i don't have to keep repeatedly pulling the trigger to get glue to flow. For a long bead run (say, on a wing that I'm having to glue for a fold) I only have to pull the trigger 3-4 times for a good amount of glue. The Adtech, I may have to do it 15-20 times for the same length.
That doesn't mean it doesn't work - the Adtech glue gun DOES work. I just don't like it as much.
Also, my Adtech has different nozzle tips, but honestly? I don't ever use the different tips because it's kind of a pain to change them out. You have to get the glue gun hot to get any glue out of the nozzle so that you can unscrew it and switch it out, which means that if you have a stick loaded, you'll get a glob running out when you take the nozzle tip off.
It's a neat idea, but in practice, you'll find that you'll put one specific tip on and then never change it again.