Not that good. I have killed one and this one is still small. It did winter over though. The colors in the leaves are beautiful. The picture doesn't even come close to the real thing.
It seems like some of the more colorful heuchs are more touchy than the others. I suppose as they further cross breed them the villosa in them becomes less and less and with it goes their hardiness.
Also, I think each one must have the right lighting site. Until you unveil that mystery the plant doesn't do well. As you know so many of mine are in large pots and I'm not sure that is the greatest place for them.
MB for me did great for 3 seasons and then vanished. This has been a very wet summer here , so only the ones with good sun are doing well. Lost too many of the ones in the shade , just rotting away.
I think Heuchera like it here. I haven't lost any at my current location yet. My mom lost all of her Heuchera in a flood a few years ago, but generally they do well here. They seem to be very carefree. They just want a place that gets a few hours of sun and not too much water.
I wondered Clint. We had some really bad flooding a couple of years ago too. We flood alot here though (not that that makes it any easier to take). Best wishes for you and your Mom.