You came down from V40 to V33. I don't think it was your best performance. You rocked the quants. So keep quants as it is and bring your old verbal magic back. You'll be golden.
I know how frustating it is to see same score again. I got 610 twice, exactly 1 month apart. Don't know if GMAC keeps a note of your level somewhere. But I'm definitely taking it again.
The schools you are aiming for are pretty demanding. So I would say, give it one more try. Make sure you have good story for taking 4 attempts, if adcoms ask. The 4 attempts can also show how hard working and perfectionist you are and how much you wanted to go to a good school. Taking GMAT once is an ordeal, but you did it thrice already. That shows how strong and consistent you are.
Keep your spirits high and do it (again)!