I have been interested in warm tolerant Masdevallias since long ago... I have purchased some "so-called" temp tolerant plants, but without much success in tehir culture...
Until I had the chance to purchase my first (and only - cause too expensive!

) Masdevallia rex and some of her (cheaper) hybrids... This one is just fantastic (rex x glandulosa) and has been for the last 6 months in the greenhouse with my Catasetinae (which means: WARM!)... I placed it outside 3 weeks ago, when started blooming, and it is doing very well... maybe with a bit lower temps I would have gotten more flower (who knows!?), but at least it is growing and blooming!
Sometimes it is reported that this hybrid is fragrant.. well... not my plant
Masdevallia Snow Cone by
kavanaru, on Flickr
Masdevallia Snow Cone by
kavanaru, on Flickr