I really like these synthesizers from the Arturia Collection. The first thing that struck me when I tried them out was how warm and fat they sound - they have a presence that is unmatched by the other (non-Arturia) soft synths in my arsenal. The dongle doesn't bother me; I just keep it plugged into a USB hub at all times so I don't have to think about it. One thing in particular that I like about these synths is that while they're all more or less comparable in terms of feature set, each one has a different interface/workflow, so there's really something for everyone. My personal favorites are the Prophet V and Minimoog.
Other than that, the "sound map" preset browser is a lot of fun; none of the synths has ever crashed for me; MIDI control is easy and the documentation is decent, if not fantastic (there's a lot of detail, but you can tell that English is not Arturia's first language).
Installation was quick and painless for me. I had some trepidation about using a dongle, but when I found I could transfer the licenses to my HD, no more worries (yes I backup regularly). The standalone's have crashed a couple of times, but I think I know what I'm doing to cause it, so now I can test customer support... but inside my DAW, and on stage, this package is awesome. I couldn't be happier overall. As a singer/songwriter, I love the hands-on creative possibilities, and as a cover band member, I love being able to recreate the exact patches from the original recordings.
Overall, I don't think I'd recommend these for a beginning synthesis, Because the Arturia V Collection is kind of extensive but if you want a lot of really thick, warm sounds you can't go wrong with these. $400 is almost a steal.