my only "issue" with UNO is that I wish I had found it sooner! I'm not real fond of the brushed metal theme in OS X. I thought about going with ShapeShifter, but there were issues with the themes that I really liked. I stumbled upon UNO, and I must say that this FREE-ware will run on my new G5 iMac for as long as the brushed metal theme is part of the Apple OS.
It was VERY easy to install, and now every window on my Mac looks sleek, neat, and exactly how it should look...in my opinion.

major kudos to the developer for a GREAT freeware application!