Astral Hawk, I agree with you in many ways. I say when you go to play at a game store you should have a army list, at least to say that you paid for what you said you paid for.
However, if someone decides to change what what wargear or whatever they have, then I'd leave right there. Its called cheating, and, frankly, I'd never play that person again. I am naturally a competitive person, and perhaps sometimes I have overlooked an inch when trying to fire at someone, or rolled an extra attack dice
, but, I'm not about to go ahead and say that my normal sergeant actually have a powerweapon when it suits me, in this instance, I agree with Fluedog.
Also, as annoying as it may be, the rulebook DOES state that you DON'T have to tell your oppenent what weapons/wargear your models have, as long as the weapons and wargear are modelled properly.