I only just found out I could play CoH again, but I do remember that when it came to the sets, I strove for the bonuses. With Posi's Blast, the damage was maxed out, still had decent accuracy, recharge, endurance, and the set bonuses with 5 of them slotted gave some very nice perks (extra accuracy and recharge on all your powers), still leaving a 6th slot for something else you might like outside the set.
I know what you mean about having the damage so high, and it's tempting to make it more balanced, but with the set bonuses, I'm not sure the other stats need to be buffed. Yeah, ED will take away a lot of the extra damage, but I always found that I didn't need to get more endurance reduction or recharge, and I preferred the little bit of extra damage I got in spite of ED.