What you are saying is what most of us feel often. ...You like the sound, but maybe something would look better, sound better, have better bass, etc., etc. The trick is to appreciate that, if a genie offered you 3 times what you could afford to pay to upgrade, and you did ALL the research, auditioning, and testing, and then bought what you found to be the best, you'd have the same feeling at some point after that, probably soon.
So, the problem is with you. Think hard about what you want and do a lot of research, and then audition in your own system if you can. I still have the same bug you are talking about, and I have taken my own advice as I just stated, and I have had the same speakers for 6 years.
Piega's are very nice speakers by the way.