I finally tried the Concubine today, and... I was surprised! It's fairly decent!
With low expectations, I did it up thermos-fu for my bus commute. (method: 4-5g in a 150ml teapot, do 4 or 5 infusions as I normally would, but dump them all directly into the thermos. So on the bus I end up drinking a blend of the first 4-5 infusions. Note that I wouldn't do this with a primo tea, but I thought it would be a good way to start using up all these samples I have lying around.)
There is a little astringency, a little bitterness, but overall the flavor is fairly thick and.. gosh I'm not good at coming up with the right tea words.. But it does have bits of that sheng flavor I do like. Let's see if I can do it, stream of consciousness, here I'll take a sip...
"Round"...good aftertaste...strong.. a tad sweet...thick... see I'm not very good at "flavor" words.
Anyway.... Would I buy a cake for $21 + shipping? Probably not.
I'll have to try this one again (preferably for real in a yixing pot) before coming up with a "star" rating, but preliminarily let's say 3 stars. "I like it, but won't be buying a cake for that price."