I have, and it's easy as shit!
The only draw, and it's not a huge deal, is you must wait 10 business days to get your money back into the account once you make the deposit. That only means you can't deposit $500 today, bet on a game, and get the $1000 put back tomorrow.
Makes some sense, since they need to verify that you actually have the cash in your account, ect.
I have used ECheck with Olympic, and you are betting in sixty seconds time. The debit is made on your account in two days usually. When I ask for a payback, I always get it credited to my account in 48hs max. (Other books my very, so you're on your own, there!)
Good luck!