Not sure which Devore model your friend has. I have Luxman 509x driving a pair of Devore Super Nine. I also have a Mastersounds Dueventi Integrated (EL34 based) in my second system. I would from time to time run the Dueventi with the Super Nine. I almost always prefer it in the triode mode as the sound is more refined. It is a solid amplifier particularly after replacing the stock tubes with some NOS RTF EL34 and RCA Clear Top 12au7, and of course, this is personal preferences. I don't have much experiences with other EL34 based amplifiers but I can say that they do sound very good as a combination. It does not have as wide and deep of a sound stage of the Luxman, however, it is still very enjoyable.
The Mastersounds amplifiers are real lookers with the round transformer enclosures and tube protectors. It makes a great center piece of any systems.