I find it the other way around, MM's got boosted because they didn't got nerfed by DR.
The defense, regen, recharge, resist based builds got the shaft. My tank went from 107 HP per second (a lot more against all MM pet, that number is for one mob only) to 63 HP, less when RTTC goes down at the first mez. A tank friend mentioned his 90% res to S/L went down to 50%.
Where did MM's got hit by DR?