Proud owner of a new M6 Carbine.
If I were to describe it in one word that word would be
punch. Super punchy, articulate, dynamic. It hides nothing to the point where I'll have to become a better player because of it.
It took me three days to get through all 49 pages but I'm glad I read it since there were some useful tidbits in there.
Specifically, understanding that all 4 voices are separate. I'd assumed based on the way that Mesa wrote the manual that voice 1 and 5 were more extreme versions of 2 and 4, but they're not. Each voice is it's own thing and needs to be evaluated separately.
Additionally, I kind of wish that Mesa would publish images of voicing EQ curves since with the power of a volume knob a lower mid scoop can easily be turned into an upper mid boost. You see this with the Strategy/Prodigy amps where people think every voice is scooped based on the description and they judge it before taking the time to understand how it'll actually fit into a mix.
Right now, I'm really digging voice 4 with my Jazz bass. Lots of mids seems to give me a lot of room to scoop on the bass without totally thinning out the the sound, and with the amp's natural low end I can go 100% bridge with a lot of punch/authority.
With my P bass I'm still bouncing around but I like both voice 2 and 4 with it. I'll need to hear how it sits in a mix before I make any decisions on this one.
What's curious is the pull-deep knob. I assumed it was similar to the deep on the D800 but it's pretty different. In a number of modes it adds top and upper midrange... instead of being a strict low end extension/boost it's more of a scoop control with some added top end to punch through.
Beyond all that, the reason I bought the Carbine is that I really like the sound of the PH410 and I wanted an amp that would really complement it. The Strategy does a killer job, but after paying to retube it I want to save it for gigs and use something a little more economical for practice/rehearsal.
I've been using the D800/Subway cabs pictured below for a couple years now, and although they sound killer they're not producing the sound I hear in my head the way the Strategy/Carbine/PH410 do... which considering the differences between the Strategy and Carbine as amplifiers I think largely comes down to me really liking that cab, and the Strategy/Carbine being voiced specifically to use PH cabs.
IMO, the D800 sounds best with it's own cabs and is too dark/warm to drive the PH410 for the sound/response that I like. Others may disagree, and that's cool as we're all after something a little bit different. You'll never know until you try for yourself.
And on a side note, a Darkglass Alpha/Omega into a Carbine is like a Dual Rectifier for bass. I prefer the sound of the amp with the bass plugged straight in as the DG's buffer changes the sound by brightening/hardening the attack whereas it's warmer/rounder without it, and the Carbine is already aggressive to begin with and doesn't really need the extra help... but, if I want the option of adding distortion compromises must be made.