Don't have links, sorry, I read it in a shop
I think Jocko Homo is right about the worst Nancies being better than the worst Marias. Perhaps we are more discerning now than we were when the format was brand new (kind of) and before we'd enjoyed the delights of ADWD.
It may also be that because Connie was nearly always the front runner we compared the good performances from the Marias to Connie's performances; with no front runner in IDA we've nothing to compare their performances to apart from our own standards. That's probably a long shot but there may be an element of truth in it. I know that personally, because I've got no background or training in MT, I can only judge on what I see and hear, and so my standard for what's good and what's fantastic, fantastic, fantastic is probably quite arbitrary.
This series has REALLY missed Zoe's input. The criteria which JB, DVO and BH uphold is bland by comparison. I know her comments were often limited to their vocal performances but I think a good percentage of the viewing public are laymen in that respect (unlike the majority of DS posters who are experts, not like me

--I wish I were!).