I used Veritas
for essay tuition since they were so good at GMAT prep. Actually not that impressed though - the guy waxed lyrical about my first draft, which I think was pretty mediocre. He recommended only small changes, which I made. Then I sent it back for a second review, but this time he said it was absolutely awful (it was, to be fair, but a lot of his criticism also applied to the first draft he liked so much). I was told to buy more edits, which I did not do.
I recommend accepted.com
, who I used for a different application - MUCH better value and I feel my essays were strongly improved. Also you can call or email the consultant with questions and for advice.
If I said something intelligent, it was probably by accident. But click "kudos" anyway - it will make me happy.