I used Vista Ultimate for about 3 months and did find it to be slower than XP.
The problem is that Vista isn't compatible with some software.
Example 1: I was updating anti-virus software for a brokerage company which went very well using AVG. The problem came about when an employee had purchased a new laptop with Vista on it and was trying to run a $35,000.00 software package and it just kept crashing. i spent some time looking over his sytem and it just wasn't compatible.
Example 2: I had intended to run Vista Business on the workstations at work (no luck). The network is running Server 2003 with roaming profiles and workstations are running XP Pro SP2. The problem with running Vista and roaming profiles is that the folder structure has changed between XP and Vista which causes some headaches. I worked on this issue for 4 days and couldn't resolve the problem since the folder redirection doesn't seem to work properly.
Example 3: My girlfriend had purchased a new laptop with Vista home premium which seemed to work just fine until we wanted to use a wireless connection the signal kept dropping. The problem happened no matter how the connection was configured or what wireless network we used.
Example 4: We have a Sonicwall 2040pro at work and Vista isn't compatible with the VPN client (it might be now).
Example 5: Vista also handles sound differently than XP does, I have a SB Audigy 2ZS which works great under XP but using Vista I get pops and snaps while playing music, movies, or games.
Example 6: Vista also has/had a huge problem with Nvidia current production video cards. The drivers available didn't work very well with the 7800 or 8800 series cards especially in SLI mode.
I would say overall Vista isn't horrible it just needs polishing and finishing. I think Microsoft should have tested Vista longer and gave us more of a finished product. I also think that the hardware vendors should be frowned upon too since alot of the issues with Vista are due to driver problems.
If I remember right when XP hit the shelves there were alot of problems with it as well including driver issues and a bunch of other problems.
I personally still like using XP over Vista so that is what I use, I do like the sidebar gadgets so I download a program called Vista Transformation Pack and installed it which gives alot of the same look and feel of Vista but using XP kernel.
