I asked this same question last year. Everyone said "yes". Every interview I went to I got a "Well, you are a bit overdressed..." The job I ended up getting, I wore some slacks and a button-up shirt and got a "thanks for not overdressing too much". I also got bonus points for having a nice bloody fingernail (thanks to Ryan's Jeep). I guess it depends on the job. In the office all the time? Meeting with customers? Doing field work?