I've never owned an HD so I can't comment except from friends. I know people that have converted from HD to Vic and never looked back. I know a couple of people that went back to HD. A lot of times it comes down to personal preference.
Saying all that. I've been riding Victory's since 06. I worked at a dealership and had my own Victory customizing business.
These bikes are pretty much bullet proof aside from the 00 and some 01 models that had the tranny issue.
The bikes are oil and AIR (thanks Jokerman for pinting that out! LOL)
cooled and you would be hard pressed to get them to overheat even in parade riding.
Vibration is less than HD but the new X bikes (short for Cross Bikes. XC=Cross Country, XR=Cross Roads) are said to have a vibration at speed where the HD seems to smooth out. That may be attributed to the new frame.
I test road two XC bikes at the Fuel It tours and they both exhibited vibration at 50+ mph. One bike was terrible (later told by the Vic rep it was a pre production demo model) the other XC was much smoother but still had some vibration.
Out of the box you have more CI and HP with a Vic than a standard model HD.
Dealers..........that IS the big downfall to Victory ownership. There aren't a lot of dealers and even less KNOWLEDGEABLE Victory mechanics. Luckily we have KevinX as a member here who is a Vic mechanic and considered in the Victory community to be one of if not THE Victory authority.
You really only need the dealer to purchase accessories and normal maintenance and wear and tear items. That can all be done through the mail.
IF you have a problem with your bike. 9 times out of 10 you can ask the question here and the answer will be given to you AND it is something that you more than likely can do on your own!
One thing you definitely need to do. Go to a Victory dealer and test ride the bikes you like. It is encouraged by Victory and the dealers know it is the best selling point.