Well...I recently helped one customer move from an older Windows XP laptop to a new Windows Vista laptop. So far so good. It did not have Windows Vista SP1 when he bought it from the store and Windows Update would not present him with the option to install SP1 because he had some .NET Framework security updates that failed to install. Come to find out, his laptop had all the correct .NET Framework versions so we downloaded the larger version of SP1 from Microsoft and installed it ourselves. It really seemed to make a difference in the performance of the laptop. He had one problem with a "no-name" USB hard drive but that was about it.
I also went ahead and recommended Vista SP1 for a customer who was still using Windows ME! 
I figured if she had to learn something new, she might as well learn Vista instead of XP. Either way, she will be MUCH happier than she has been with Windows ME! 
I figured if she had to learn something new, she might as well learn Vista instead of XP. Either way, she will be MUCH happier than she has been with Windows ME! So...I still issue the Vista warnings regarding older hardware and the non-SP1 version of Vista. But if you have mostly newer printers, scanners, monitors, video cards, and external hard drives, you may be fine with Vista. Just make sure you get plenty of RAM.
-- Jeff