Yeah - I use guitars with 10's for rhythm, and the 9's for lead (and rhythm as well if I'm playing live). No question that the 10's give a fuller tone.

Only re-posting because I really don't see a problem with using 9's.... especially if you're already happy with them. Going to 10's will also mean having your guitar re-setup, which maybe you'd prefer not to do.

I wouldn't want you to get the impression that 9's are no good....