Giana, I think your fears are well founded because there is a truth behind them. I'm not going to go as far as "discounting" the success of critique group artists but I will recognize that it's the product of a artificial system imposed on the main gallery. People in the group haven't earned their hits/comments by appealing thumbnails or developing a fan base but because they signed their names to a list and implicitly agreed to comment on other people's work within the group. Look at next week's "50 most popular artists" list, it'll be dominated by the critique group. Why? Because they signed their names.
  I think the critique group is a positive thing and hopefully the emphasis will be on quality critiques, I'm just saying it'll render a lot of stats meaningless (which people shouldn't be concerned about anyway :-)).