Which Mafell? The FM 1000 WS, with its “tool-less quick-clamping device?” It’s kind of an interesting comparison to the AMB 1050 FME-W DI, but according to Mafell’s website it’s a 230V 50 Hz device.
Ignoring that, the FM 1000 WS is fascinating. It isn’t a tool changer, but it should allow easy manual tool changes, which is probably good enough for a lot of uses. The Mafell looks like it sells for EUR 530, vs EUR 1,200 for the AMB. AMB toolholders are pricy, too, and the AMB needs extra hardware for driving the ATC as well (a compressor and a couple solenoids at minimum). So effectively speaking, the Mafell is 1/3rd the price.
They both claim similar power–1050 vs 1000W.
The AMB uses ER16 collets, and will take up to 10mm or 3/8" tools. The Mafell only takes 8mm tools, unless you use an adapter sleeve. They sell a few metric sizes plus 1/8", but no 1/4". It looks like they make some sort of collet attachment, but I’d be worried about runout in that case. It shouldn’t be that hard to find a 3rd party 1/4" to 8mm sleeve.
They both weigh around 3 kg, vs 20+ kg for a lot of Chinese ATC spindles.
The AMB uses a 0-10V line for spindle speed control and can do 5,000-25,000 RPM. The Mafell lists 4,000-25,000 RPM, but doesn’t say anything about external speed control, so it probably uses a dial.
All in all, it looks interesting, but I don’t see any easy way to power it in the US. Also, I’d miss the ability to directly control spindle speed via gcode, but I could twiddle a lot of dials for $1k.