Robbeasy: It's wierd with using the PM wordage to find out information - as Town you have so little to go on that everything matters, right down to how you refer to yourself or the scum. I DONT feel its cheating in any way - we use the tools we are given in any way we see fit, and it does provoke some pretty good debates. If a MOD doesn't want us to use these things, then the PMs should be more carefully worded, IMHO.
Overall, I think it added rather than detracted from this game - but I guess its all a matter of taste.
Saying: I am a "vanilla townie'" is perfectly fine. Saying "the words 'Vanilla Townie' are in my PM, thus the other player must be town" is against the rules, generally speaking, since it is quoting. Not playing by the rules, is by definition, cheating. That
isn't a matter of taste.
From my point of view it totally detracted from the game, as it created an imbalance that was not intended in the setup. From Day 2 on, there were always several character that were pretty much completely confirmed. It limited viable NK targets for scum, and also made it easier for town to pass with powers.
In the end, if the moderator doesn't mind quoting in his or her game, the moderator can adjust the rules accordingly. If it is in the rules, however, it should not be a matter of debate.