Head arrived a little bit ago. Very nice! A few of quick observations:
1) The 'flat/neutral' setting is a bit uninspiring to my ear. No big deal there, but very different from, for example, the MB or Tecamp stuff that sounds full, fat, even and forceful right out of the box
2) It feels more like a 'lightweight full sized head' than a Micro. This also is not a bad thing. It has a bit of the look and feel of those Panasonic 'Toughbook' PC's... very sturdy, with a thick metal case. Nice... still only around 10 pounds.
3) The Ampeg heritage... I can sure hear it, but it is much better... warm and fat, but still quick and accurate. It LOVES my 60's inspired J bass with nickels and a RW board... fabulous 'old school meets new school' tone.
4) The tube emulation control is wonderful. At low levels, it is warm and fattens up the tone, and adds that 'tube like' complexity with no distortion. Nice, and it reminds me a bit of that Carvin B1500 drive control at low settings. It will snarl when cranked, but that's not my thing.
5) Tuner... much better than I would have thought. It tracks quickly. It won't lock into the B string in 'real time', but in the more exact mode it goes into when muted, it works great on the open B. VERY impressive, and this comes from a guy who uses the amazing Sonic strobe tuner regularly.
6) EQ points.... they look strange on the spec, but work perfectly (at least with my AE410). The bass knob is more like a low mid knob with more balls... nice... fat without boom.
7) I can hear that 'tube emulation' sort of limiting thing when I push it. Very different from the TecAmp and MB stuff that stays very even and exact right up to the point of the limits of the amp. I like it, and it is very convincing sounding... that 'tube soft compression' when pushed. Again, not my thing, but IMO, well executed.
Haven't messed with the compressor yet, or the EQ shift. Quite frankly, I can tell already I would have been just as happy with the 'Classic 450', but I'm glad I sprung for all the cool lights and buttons
Very nice, and a great execution for those who dig a more rock oriented tone but want it small and light. I like it very much so far.
I'll post up more detail versus the Marbkass F1 and LMII after I spend some time. I guess I will just say now that for those who like the TF550b with the AE410..... buy one of these today!