I absolutely despise MS now that they FORCED the ribbon onto us. As a power user, I am annoyed by the amount of space that the ribbon takes up, but worst of all is the inflexibility of it.
I have specific tool bars for several of the workbooks that I use throughout the week. It sounds like you can customize your own ribbon in Excel 10, but you still don't appear to have the flexibility of Excel 03.
I got a new computer at work a few weeks ago. I had them remove Office 7 and put 2003 back on. MS: I can go for years without an upgrade. Do the right thing. Those who don't use the cool features are unlikely to start using them just because you stuck a slick, productivity-killing ribbon at the top of the screen.
You are alienating your most loyal customers.