His first album, recorded while he was still in Heep, is excellent. Tracks like "Man full of yesterdays" qualify him for "Heavy prog" in my opinion.
He was sacked from Uriah Heep because of his problems with alcohol, an illness which was to blight him untill his death. His subsequent albums suffered as a result. "Baby faced killer" has some good tracks, but it was very variable.
Rough Diamond's album was the same, some of it was really good, but a lot of it was marred by Byron's inability to focus. For me, The Byron Band album was a sorry end.
It should be remembered that although David was initially one of Uriah Heep's main songwriters, Ken Hensley quickly took on that role. I don't think Byron was capable of writing an entire album of top quality material on his own.
Had David been able to get his drinking under control, I am sure he would be back in Uriah Heep today. His song "I remember" says it all.
By the way, did you know he used to work with Elton John when they recorded anonymous cover versions of pop songs for budget LPs. Some of the songs he did are available on CD.