I have used the Atma-Sphere MA1 MkII.2 (140w/ch compared to M60's 60w/ch) with Kharma Ceramique 1.0 speakers in the past. I have not tried the Joule's or the Lamm's, however.
I ran an Audio Aero Capitole CD player directly into the Atma at that time. The Atma-Sphere's are remarkably transparent and revealing while at the same time provide so much of the harmonic content of instruments and vocals...they really make gorgeous and, most importantly to me, lifelike realistic sound. They pass on an amazing amount of detail in a totally natural way...no hype or etch to be found...just wonderfully natural detail. I would give the Atma-sphere amps serious consideration!
As to what Mixalis commented on, I don't think this is possible with the Atma-Sphere OTL amps. They have a bridged output circuit which protects the amps and speakers against such a failure if I'm not mistaken? There have been many documented cases of catastrophic tube failures that neither damaged the amps nor the speakers...just had to replace the offensive tube.
Most recently I've used a pair of MA1 MkII.3 amps to drive Magnepan MG3.6r's (truly an amazing combination despite most comments regarding the need to use BIG powerful amps to drive the maggies) and Vandersteen 1C's (while I wait for my Ridgestreet Audio Sason LTD speakers to be completed). Compared to driving the Maggies and the Vandersteens with my previous amp (Parasound Halo JC1 mono's), the Atma-Sphere amps brought each speaker to a MUCH higher level of realism from top to bottom...surprisingly, including the bass. My friend and I both feel it insane how good the $750 Vandersteens sound being fed a signal through the Atma-Sphere amps. Seriously, I could live with this long term...it's ridiculous to have $30k worth of electronics driving a $750 pair of speakers, but it makes some beautiful, and convincing, music!
FYI, I am currently feeding the Atma's via a BAT VK51SE (very nice match) and the BAT is fed via Esoteric UX-3 Universal Player with Statement Mod from Steve Huntley at GNSC. After having run the Atma-Sphere's direct via the Audio Aero Capitole and more recently via a Resolution Audio Opus CD player, I prefer using a high quality preamp, rather than going direct. I may experiment running direct in the near future just to make sure, but the synergy with the BAT is impressive.
Good luck...I'm sure you cannot go wrong with the Lamm's, Joule's or Atma-Sphere's...all are highly regarded.