Anyone had a valet from Sytner?

[red or dead]

Hi guys, I've got a frre voucher for a valet from Sytner Audi but was wondering if it's worth using?
I ALWAY'S wash my car myself having had a bad experience with swirl marks on my Clio 182, was just thinking wether or not to risk letting the guys at Sytner do it for me or is there a chance I'd end up with swirl marks allover the bodywork?

Thanks in advance for any advise.

Michael.