I would say, that eldar are NOT broken at all.
I don't want to boast, but in last year I have not lost with my ulthwé list(and it is not because I didn't play a single game :-))
It is strong seer council, which gives fortune on itself + guardian squads and has augmented mind war(chance 168/169 that it will augment all mind wars, it is 5 farseers+11 warlocks)
+spiders with exarch -hit and run (power as well as tactics)
Two big (about16+2)squads of black defender guardians with starcannons
+2 wraithlords.
I think that the seer council will show, who is psyker here, because after few turns, there are no heavy weapons, no HQ and such things.
Yes, generally, some units listed above are too expensive (although I think that the guard is just good, maybe rise the cost to 45 and give them 2+ save)
In codex, there are strange things - why the save of that girl with Ld armor? There are 6*6=36 possibilities, she fails, when she rolls 12[6;6]
11[5;6] [6;5]
10[6;4] [5;5] [4;6]
That is 6 possibilities. So her chance to fail is 6/36=1/6=2+ invul save. And in time of the codex, there were no Pariahs to lower it.
And the Avatar is too weak I think. With his 5+ invul save, he is pushing up daisies a little too early.
Reapers...Lovely models, but the cost!!! When 5 men squad shoots at marines, they kill 4-5. When one devastator squad with heavy bolters shoots at reapers, they kill 6(only with HB, not counting bolters). OVERKILLLLLL.
And...in eldar army, you don't pay for units, but for possibilities of combination. Some SM guys say, guardians suck with their 5+ save, bolters smash it to pieces. Well, they are right. But give there warlock and now, it is, hey, those guardians aren't that bad. But let them re-roll it with fortune and you will hear:CHEEEEEEEEZY.
Spideys are a bit other case. Alone, they are great (in my opinion, I heard even they suck), but with hit and run...unbeliavable. When your opponent "catches" you with happy smile, you just jump away and tear him down.