I've never used or even heard a Vader before, but I've always regarded them with suspicion for recording - a cab company that prides itself on power handling over all else, I dunno; I've heard they punch amazingly live because of the speaker headroom, but I could easily see that translating to sterile and thin sounding under a mic. Get yourself something with Vintage 30s, I'd say - it's not like it's impossible to get great results from other speakers, but you'll never find one more tried-and-true than that!
Also, I don't know how you have the Savage dialed in, but there sure is a crap-load to tweak on that amp, so that might also be a culprit...