LOL, romanov - you say a 780 is "pretty decent"?? You should be very proud of that score!!!
Not sure what a "dismal" essay score is - did you get below a 5.0?
We've rarely recommended retesting simply to raise the AWA, but believe it or not, this is becoming a more important part of the test, simply because EVERYTHING is becoming more competitive and the schools are looking at everything they can in order to evaluate candidates. The AWA used to be almost a throwaway part of the application, but not any more. And, because you did so amazingly well on the verbal and the quant, it should be easy for you to score equally well on a retest. So there would be very little risk, we think, and potentially some worthwhile reward, to retest in order to raise the AWA.
The reason for this advice is that if your AWA is very low, and your application essays are done well, then the adcom may feel that you had help with them. This would not be a good thing (they might think that, even if you wrote them entirely on your own!).
Very few schools would actually reject your application based entirely on a low AWA - they will look at the entire package, and this is a tiny weakness in the grand scheme of things. BUT! it is an unfortunate disconnect that could make them wonder. We've even heard of one admissions director who is adamant that she would not accept someone with a mediocre AWA score (most other admissions directors we've spoken with say that's a little extreme).
So.... this probably isn't a huge risk for you.... but if you were up for it, it also wouldn't hurt to go for that test again to fix it.
Of course, if you are simply overreacting - if your score is 5.0 or higher - then you truly have nothing to worry about.
EssaySnark