Wasn't DS3 and VS1 the samething except DS3 added a couple of characters that wasn't in VS or some crap?
When VSav got ported to home consoles as DS3, it included all of the characters from the arcade release, plus Phobos, Pyron, and Donovan from Hunter/NW. These characters are banned in tourneys if you're running it on a console though. Fortunately, practically all VSav tournies are held on cabs anyways, so it never really comes up.
PSP version is basically a port if Vampire Chronicle for Matching Service on the DreamCast. It's basically the " Hyper" version of DS that allows you to play all versions if the characters from each iteration.
And it was awesome. I feel like there was a whole lotta depth in that game that never really got explored.