I recently got to hear the Viva Solista tube integrated in a friend's system. That is a terrific, albeit expensive, integrated amp. It is a single ended triode using 845 output tubes. It is quite funky in that it uses two 211 tubes as rectifiers!
The sound is warm and relaxed without being sluggish or murky. It is also dead quiet as far as noise (my friend's system is about 105 db efficient, so quiet IS a big deal).