We used Winner this past June -- granted it wasn't busy season, but it was great. We made the reservations through
AirportParkingReservation.com. You pay one day up front and a small service charge ($4), but the rate is discounted from Winner's standard rate. ( It's $6.89/day at the moment; I think that's what we paid.)
Winner was a "valet" service and I really liked it. You drive to their lot, check in, and one of their drivers gets into your car and drives you to the terminal. He helped unload the bags (which the SkyCap checked in for our SouthWest flight). On the way home, you call them for pickup. They ask you to call once you have your bags--apparently some people call as soon as they get off the plane and the Winner driver can end up waiting a long time. I'd recommend calling sometime in between. When we fly Southwest in December, I'll probably call once we're down to baggage claim while we wait for our bags. We ended up waiting a bit (10-15 minutes) last time. They help you load your bags back into the car as well.
We opted for the "Express" return service. For an extra $10 or so, when they bring your car back to the airport upon your return, you can just drive away rather than ferrying the driver back to the parking lot.
It was really nice not having to deal with a bunch of suitcases on a shuttle bus with just my wife and a 5 year old. And the only thing that I think really cost more than the non-valet services was the express service on arrival. I'd imagine that in winter it'd be nice to have the car warmed up when you get into it, too--even if you do ferry the driver back to the lot.
Here's their direct
link but I'm pretty sure it's noticably cheaper if you make the reservation through Airport Parking Reservations. Also, I'm not sure if they mention it in the directions, but they're behind the Winner Lincoln and Cadillac dealer.
Keep in mind that there's a 15% City Parking Tax. Our total without tips for 8 days including the express drop off was $77.04.
I liked them and we expect to use them in December but your mileage may vary, of course.
Brett