Well, in a real record store that caters to DJs you just listen to it before you buy it. Since this seems to be an official release, its probably somewhat OK, but its anyone's guess as to it being good or not.
Since I'm not hip to "DP", I don't know if these are for sale from a person on a forum or in an actual web store. Can I just buy this for $10 or what?
Either way if you think, "DJ = someone who plays records and sometimes scratches them back and forth as homies spin on da cardboard." then you are almost certainly not going to like this no matter what it sounds like. My guess is that it would fall into the "bad trance" genre knowing Japan and Konami and all that, but its anyone's guess.
EDIT: I found a review of the CD that has both of these tracks on it (or at least versions of them).
http://www.soundtrackcentral.com/cds/draculax_remixies.htmEDIT 2: This 12" seems to be 10 years old, so probably not easy to find. I just pirated the Fei Long thing. Its a sort of pidgin pastiche of different styles of house using some phased samples from...some game, not sure which one not being a huge Vampire fan. Basically I won't be seeking this record.