Vista wasn't unmanageable, no, but it does hog a lot of system resources, and for a computer that I use extensively for heavy applications, that is something I do not look fondly at. It also isn't good when customers do not know much about computers and refuse to get more than 1GB of RAM or even 512MB. Then of course there are security boxes that pop up no matter how many times you give permission and all the extra work you have to go through just to get a program or game to work properly. Like I said, it's manageable.
@gustave, If it doesn't crash on a live tv presentation, then it probably wasn't made by Microsoft.