i spent 2 weeks with the Atmasphere MA2 mkII.2 and 1 week with the Tenor 75Wi with my previous speakers, the Watt/Puppy 6. both were excellent......easily the best 2 amps i have ever heard.
the Atmasphere was perfectly matched with the power hungry WP6.....plenty of power, no dynamic limitations i could perceive, excellent extension and resolution, with ease and purity. in fact, i was ready to buy the Atmasphere........
then i heard the Tenor. not as perfectly matched to the WP6, good dynamics within it's performance envelope, but at higher than normal volume levels it could get hard on peaks or go into soft clipping. no problem at normal listening levels. but the Tenor was more extended and articulate in the bass, had better clarity and refinement, and was faster than the Atmasphere.
i bought the Tenor, but also got different speakers. my recommendation for WP6 speakers would be either the Tenor or the Atmasphere, depending on listening priorities, size of room, and musical choices. you will love either of these great amps. OTL is the only way to go IMHO.