I have also used Winner valet and it was nice.
You drive from their site to the airport in your own car, so you only have to take your stuff out once at the airport. Then on your return, call them once you have your bags and they are there in minutes.
It isn't any more expensive than the lots and if you have
AAA you get a discount. Also if you get those Valpack coupons they sometimes have cheap rates that include the taxes. They also accept competitor coupons too.
You also have the option on your return of paying extra and then you can leave straight from the airport without having to go back to their site to settle the account.