I've created a couple of userlists (and seen a few of yours, very nice!) but for me the real value in userlists is aggregating cards from different sets into a single grouping. Like I said before, it's not really a big deal for me to mentally exclude the cards that I, in my infinite wisdom, don't want to include. ;-)
It would be nice to be able to exclude on a note by note basis, just for the hall of fame lists, but the value added would probably be less than the effort required, so it's not a big deal.