Are you just talking about the Rectifier amp, which I have, or about something new? The Rectifier itself is fabulous for recording, especially for a heavy guitar tone.
I only know it by 'Rectifier Recording Preamp'--it's not a power amp--looks to be 2RU or 3RU. Maybe it is just out--I dunno. I've only looked at the marketing literature, and got very, very curious. In fact, I believe I started to salivate.
I dont have experience with it but I am under the impression that much of a tube amp's sweetness comes from the power section, unless you are in a situation requiring low volumes it would probably be in your benefit to just mic a real speaker.