I have never been as down on Vista as many other people. If you run Vista on fairly decent, newer hardware it performs quite well, and it is much more secure than Windows XP. People seem to forget how much whining and complaining was heard about Windows XP in 2001-2002. Lots of people hated the Luna interface in Windows XP, and security was still a big issue until Windows XP SP2. People also liked to complain loudly about poor driver support in the early days of Windows XP.
Microsoft was deservedly criticized for poor security in the 2003-2004 time frame. Windows XP SP2 was a huge improvement on the security front, and Windows Vista is even better, (even though UAC is badly implemented and universally reviled). The truth is that you have to make more of an effort as an application developer to write software that is secure and functions correctly without local admin rights (like in the "good old days" of Windows 2000, where everything was installed and enabled by default).
At any rate, Vista has improved quite a bit over the last year, and the upcoming release of SP1 will continue that trend.