We have used this place several times. Their online specials are hard to beat. Left my car there 12 days and it cost less than a cab both ways to Cleveland Heights. Never waited more than a couple of minutes after parking the car for the van to pick us up. And I've never waited more than 5 minutes after getting off a plane for the van to take me back to my car.
I never feel like I'm sacrificing more than a minute or two for not parking at the airport. In fact, in some ways it is easier than using the on-site airport parking. Your car is in the open, but it feels really safe.
There is ALWAYS a van waiting at the arrivals gate. No small thing in a Cleveland winter. Got in about 11 PM tonight and the van driver waited until I started my car. I really appreciated that after 2 of the coldest weeks Cleveland has ever seen. They usually help my wife with her bags. All this and no tipping.