I played through an M6 & M9 and could not for the life of me get them to even start breaking up like my Walkabout did so well. Yeah, to get the tube sounds you desire you are sure going to need some help.
That's the whole point of these heads IMO, and why I describe the M6 as the 'Mesa for those players who don't like Mesa'. While there is a tube in the pre, it's not like the multi-tube simulstate pre's in the other hybrids. It's more of an Eden or SWR type tube 'flavor' that adds a bit of 'character' while still staying solid state tight, punchy and clean short of cranking the gain all the way up.
This is reflected in the marketing materials and product descriptions in the M6 ad copy.
If you want that classic Mesa 'all tube amp tone' in one of their hybrids, and still want the massive ooomph of the M6 (I can't even imagine the M9), then the Triton is probably the ticket.
IMO and IME.

