I would probably stay away from 18K gold for an "everyday" watch, however, I guess it depends on how you define "everyday" and how fussy you are. Do you mean get up in the morning, take a shower, put your watch on, and off you go to work? Or do you mean that you truely wear it everyday - like when you go to the beach, golfing, health club, coaching the kids LL team, playing frisbee with the dog, etc?

I have an 18K gold and stainless watch that I use for the above, and it has collected some scratches. However, to me it is not that big of a deal, so it doesn't bother me.