I think they're very under-rated, because of experiences like Bigjoes. When I was a lad, I sold Carver gear, and quietly laughed whenever someone bought it, because to my ears and college student's wallet, it was a bad decision.
The Sunfire is complete opposite. Lots of performance for the price, and the closest to tube type sound in its price range. Their HT amps are very competitive with much higher $ designs. They also run cool compared to other high power amps. They drive anything, and appear to be well made. Are they the most refined, no. But when I couldn't afford the big tube amps I craved, this was the next best thing.
Spencer