I could see a blend being a possibility. It only sounds quad tracked during the choruses to me, though. It could be a modified Recto, but it sounds like a non tube-screamer esque boost was used, passive pickups were the weapon of choice, and possibly some pre-input eq was done.
The fact that the low end doesn't sound like a Rectifier may have a WHOLE LOT due to his playing style/guitar/pickup choice. Ermz, you know very well by now that certain DIs (or certain players), make amps sound either awesome, mediocre, or like complete shit. I actually want to do a comparison like this soon with two people's DI tracks. Does anyone here have a Fireface800, a Countryman and an EMG equipped Les Paul? If so, let's both find a riff, play it, and I'll reamp over the same backing tracks!
The most interesting blend-style I have ever heard, is that Cantrell used to quad track and have two of the amps highpassed and the other two lowpassed and actually had one amp doing the meat portion on each side and the other doing the sheen and treble.