The thing is... the MOP expansion is much more than just 13 ilvls... and the gear will continue to scale abilities and make them more and more unbalanced. What was 10% over 13 ilvls - becomes 100% over 130 (we are already at 100 ilvls now after patch 5.2).
Blizzard will not do anything this expansion to fix the problem gear scaling is causing. To do that they need to change every spell in the game to scale exactly the same and that simply will not happen. And again - THAT is why the extra amount of ilvls are the WORST thing Blizzard can be adding to the game.... but its the ONLY thing they are doing at the moment.
---------- Post added 2013-02-05 at 04:23 PM ----------
The scaling is and always will be a problem. You talk about the 5%. BLizzard is now all of a sudden talking about 10%... over 13 ilvls of gear.... Scaling is STILL a major problem and even tho its not as big of a problem as in Vanilla - it will still do alot of damage when Blizzard is adding so huge ilvl inflation into the game as we are now seeing.
The real issues we will start to see now is with the healing classes since they will have more mana regen than before. This leads to the big expensive spells to become better - and some specs have the abilities to have both hots and casts spells at the same time - while others dont.
But before you go claim scaling is fine... We have yet to see ANY public tests with 5.2 gear. What we do know is that we can NOT trust Blizzard when all of a sudden the start talking about 10% change in 13 ilvls ... when we were expecting REAL balance over the entire expansion.
I get your point of the entire expansion, but Blizzard does rebalance during each patch.. so if the devs balance something at the beginning of a patch, you only really have 3 months or so (ha) for scaling to cause things to unwind. I am sure it is with that in mind that GC asked someone to prove to him that scaling would be an issue. If the devs only balanced classes at the very beginning of an expansion, and then you had 100 ilvls of gear changes, then definitely I could see classes become very unbalanced.
And that is what GC is asking. Show him a spec that because of haste or spirit (primarily) gained within a tier, that spec will go from balanced at the start of the tier, to more than 5% OP at the end of the tier. Is there a certain crit, or haste threshold that will drastically alter the rotation of a spec to allow them to do something new that gains them that much of an advantage. Is there a mana-regen threshhold at which point a healing spec can drastically alter what spells they are casting to the point where they are now drastically better than the other healers who also have gotten similar upgrades?
That is what GC is asking.. show him the mechanism for a spec that allows gear to create those type of drastic changes in gameplay within a tier.