I've heard that the ilvl% from Warcraftlogs isn't the best way to evaluate someone's performance (because of boosting and different fight lenghts) but doesn't it give a good picture when the comparison is done between members of the same raid group?
Example: we have a hunter who's constantly below 25% compared to other hunters from the same ilvl bracket and a shaman who's constantly above 75%. Is it safe to say that the shaman is playing a lot better?