How do ARC's latest amps stack up to Lamm?

With ARC's newest REF amps being highly regarded, how do they compare to something like the M2.2 or ML2.2? Assuming the Lamms are better, would they be a huge step up from the ARCs, or not necessarily?
The ARC amps make a lot more power than the ML2.2 and would suit a much wider range of loudspeakers. But if you have the right sort of speaker, there is something pretty magical to the sound of the ML2.1 (which I own), and I assume the ML2.2 is cut from the same cloth.

What speakers were you going to pair with the amps?

I own the M2.2 LAMM rated at 220WPC. Stereophile measure the real power
on a bench test at 300WPC .So honestly this model got "balls"
and was driving effortless my former ANDRA 3 speakers and actually my
SONUS FABER EVOLUTION. From what i heard with ARC product i do think
that the LAMM products offer a more delicate sound by a good notch. My
humble opinion..... + the M2.2 are not full tube but hybrid design offering the
best of both world: GRIP and FINESSE