I've been playing on these for a couple of months now. I'm pleasantly surprised, they're well-rounded; bright, but with no metallic harshness. A hint of warmth. On my viola, both the C and the A are nice-sounding.
In fact, I would consider this a strong contender, if not a substitute, for Dominants as a mid-range, default option for a neutral sound. I feel like they do well in an orchestral setting.
They just seem to lack a bit more colour for variety and expressiveness.