I have been using vista since the first beta came out. I did have some initial problems with a few things. The biggest problem was my network card incompatibility. Thankfully, I have a wireless card on my pc that did work with vista. So, I was able to get the driver for my real network card. Since then, no problems at all. I also have the new office and I have learned to save as an older file once I sent out a few invoices that nobody could read
There are a lot of cool features and it really only took a little while to get it right. But, I wouldn't even attempt to use it on a pc that is even a year old.
My PC did say Vista ready and it still had some problems.