The comment about recommendations that I was already recording was the actual behaviour of one instance of the old system. Then, IIRC, it was changed to remove the stuff that was already marked as being recorded or a favourite.
But it was done by getting the top 10 matches with what it thought were my preferences, then removing the stuff I'd already marked in IceTV. So instead of giving me ten recommendations, about half of which I'd already marked, it gave me half as many recommendations.

I'm sure there must be a better way...