I just ran a 180/55/17 slick on my 04 on Sunday. I have always used the 190 on mine so I was a little hesitant about using the tire.
For the record it does work and many people like this size, I'm not one of them. I much prefer the 190 to the 180. I did improve my lap times by 2 seconds but I think that's more due to the fact it was a slick than the size, I just didn't feel really comfortable on it.
Then again your not asking about DOT verses Slicks so I guess my opinion is null and void anyway, sorry.