As was found out here http://www.swtor.com/community/showthread.php?t=727762
, FOTM classes are more likely to get top tier Season 1 rewards than non-FOTM classes.
I don't like this inbalance.
I have the suspicion that the number of Healer Sorcs / Sages who are getting top tier rewards will be the smallest number of all classes.
However, I have no actual data for that; this is just an suspicion growing after reading various PvP threads about Sages / Sorcs being viable as healers.
I also believe that - accordsing to the Leaderbords - far more Empire faction players will get top tier rewards than Republic faction players.
Which is another inbalance.
As I've noted before, ALL ACs will be represented at 1500+. There are some specs that will make it significantly harder for you to obtain a high rating on, but if you are a skilled PvPer and want the rewards, you can get them with any class
. Stop trying to force your spec through and swap to Madness/Balance for Sorc/Sage.
Faction imbalances certainly exist, but the dominant faction changes by server. Also, faction does not matter in terms of grouped rating since you are only reliant on 3 other people being good, not randomly matched with anyone on your faction. If you truly want top tier rewards, you are definitely better off removing the RNG element by doing 4s.