I ended up listening to the album at work after downloading it the night before. Now I'm playing it again so it scrobbles on last.fm. I'm not sure if I can even comment on the quality of all the remixes, because the quality is just there. Good music is good. I hadn't even looked at the artwork until a short while after listening to it. I'm interested in a physical copy just so I use it as a conversation piece on a shelf somewhere.
As for the vocals: I may be nostalgic for the game, but I don't let that cloud my judgment. Then again I've been calling it Diddy Kong's Quest when it's actually Diddy's Kong Quest, so maybe my memories of the game aren't as strong. I think the vocals were implemented well, and I particularly like the concept of Nicole's track.
Congratulations to everyone involved in the project!