I'm an art consultant. I work for myself, and wear whatever I like whenever I like
In the past, I've gone to client meetings in Casios, and reps of Rolexes, Omegas and PAMs (not all at once, of course ) To date, I've never had a client comment on the watch I was wearing, or even appear to notice... Infact, the only person to ever spontaneously comment on my watch, was a friend.
If you're working in an office, I'd say consider these points:
1. What does the majority wear?
2. Do you want to blend in with the majority, or stand out?
I remember reading that, in office politics, don't dress like your boss. Dress like your boss's boss, as that shows a more 'longterm' and professional attitude.