Wolfram Christ can be a boring performer (witness a deadpan Berlioz Harold in Italy with Maazel), but these works seem to suit him perfectly.
The J.C. Bach Concerto (is *that* really J.C. Bach???) is quite splashy, especially witness the final movement. It's very exciting, and definitely worth exploring, with a tuneful first movement, and a lovely second. The first theme of I comes back to haunt in III, making it a "cyclical" work.
The Stamitz is well known to any violist, and is a very rewarding concerto, regardless of the instrumentation.
One reviewer stated that these works are not "virtuosic". That's a judgment made from the twentieth (twenty-first!) century: in their time, these works were considered to be very much the fare of virtuosos. The attitude that only modern or romantic works can be virtuosic (vis-a-vis the viola literature) miss the point. In any case, even music without lots of notes or string crossing, double stops, etc., is MUCH harder to perform; witness Mozart, where so many performers spin notes but don't make music. Conversely, virtuosic affairs by Sarasate or Paganini may have all of the fireworks, but no soul--the performer only need play all the notes.
Anyway, I'm off the track. Explore this recording; it's rewarding!