Thanks for the cheese, Boofer (and Ann - I neglected to say thanks in my previous post!).
Bitterness is not the right word, but I can't think what is. It is just a sort of deep note that comes at the end of the taste; an added complexity. It is not a bad taste, just a slightly different nuance than my true cheddars.
All that said, I don't think I am anywhere near a "nutty" taste, as indicated in the link. If I ever find a source of raw milk, I need to try again with that; I suspect that would make quite a difference. Also, it appears that the cheese in the link is left with a natural rind rather than bagged.
Bottom line is that this is probably nowhere near a true Cantal ... but it is quite good, and I am enjoying the first quarter of it!