Dan Hannum: Yes, it's an upright bass test. I use the Gnome with a SAD 112H box (Fostex-Ferrit-speaker + a double-bass-friendly horn, but nothing special; SAD is a 1-man-company in Germany). I sold my MB Nano I about 2 years ago because some upper mids were too much for me, but now I have installed the Schertler Stat B Pickup in a different way, maybe I would like it better now. Like you I'm finicky regarding mids, I would like to try the Nano in direct comparison to the Gnome now. They have issued a Nano II, hm, I don't know about the differences. The Nano and the Gnome have a very quiet fan, comparable to a laptop.
Both are great amps worth trying. To me the Gnome is loud enough for DB and I can transport it in the Bassreflex-Channel of the box. In comparison the Nano is huge, has more power and more features like an effect loop. I also had a BAM 200, but to me it was noisy (hiss) and had nearly no headroom. With "amp that ran cooler" you mean the fan? I don't remember that the fan of the BAM was very loud, but the Gnome and the Nano are definitely more quiet.