I didn't see the whole episode (and given that I've gotten out of the habit of watching television at all the last several months, I'm not sure if I'm going to be keeping up much with it or not over the season), but I did like the blonde who sang "Piece of My Heart" and the guy who sang "Roxanne". In the latter case, yes, he did have limited range (as the panel stated) but at least he did his own thing with it and as far as I'm concerned improved on it, but then again I don't like that song anyway and part of the problem I have with the original is Sting's caterwauling all over the place, so toning down the range I think actually helped.
Based on the "highlights" shown at the end, among the people I missed, I liked the other blonde woman and the bald guy who sang "Satisfaction".
Overall -- and this is just based on what I saw -- I don't think this group collectively has the amount of talent that the group they had last year for INXS.