"Now aside the fact, that I have no problems with routers or"
Many users had to upgrade the firmware of their routers or replace them (if unsupported) because of Vista autotuning (there was even an article on slashdot about a full provider having that issue), because Vista requires a special non-standard OPTIONAL DHCP flag that many routers don't support to get an IP address. Sources: (1) (2) (3)...
"Windows Update"
lucky.
"high CPU usage with WMP" "or audio skipping..."
Because you have a core2duo, try on a slower machine (like an Atom-based UMPC) to play a video on WMP both on XP and on Vista and you'll see an huge speed difference, it's so huge that even putting the mouse over a tooltip could make the video skip (there's even a funny KB about the issue on Microsoft's website. Solution? Don't move the mouse while playing...).
"What's so great about that longhorn video? That's something I never got. The redeeming GUI features of the OS that is featured in that video seem to be flying pictures in the explorer and flashy effects."
Longhorn was set to be released 3 years before Vista and was planned to have major changes not just in the UI but Microsoft decided to do a "reset" of Longhorn development because they couldn't finish it in time and all people got was an OS with a superficially pretty UI where many features were delayed, cut or just left half broken because even after the reset they had to rush to avoid releasing something outdated. That video is not so amazing according to today's standard but it was really astonishing in 2002-2003. Vista was really too little and too late and the high hardware requirements, bugs, missing drivers and that resident unfinished feel certainly didn't help its image.
"The biggest cause of the negative image that portrayed Vista is exactly the post above me (Evil SEO). FUD, plain and simple."
If mine's FUD yours is plain ignorance. Come here and counter all of my points, if you can. I can find plenty of news or forum posts that prove that a lot of people had those issues, can you prove the opposite? I dare you, counter all of my arguments properly, then, and only then, you could call them FUD. Come on! Don't be scared! I'm waiting..
