I have wondered about the 44 mags EHX pedals!! Those sound like a killer backup, but only 44 SS watts may not cut it for Jim, me either. I wonder if you can stack them?
I know I'm in the minority camp on this one... If you bring 300w of guitar power across multiple speakers to a gig I'm sure you are gonna have a nice size PA and if you have a nice size PA you are gonna have mics and monitors too. So if you have a breakdown, plug in the 44, mic her up, and get some extra, if needed, from the monitors.
44 watts is just about 2.5 to 3 DB quieter than a Twin reverb.