I HATE valets. Generally I will park myself unless I'm going somewhere that is 100% valet.
I was on business a few months ago, and my bank put me up at a fairly nice hotel chain near the conference location. It was 100% valet parking at the hotel, so I had no choice.
First morning I get my car? They punched a freaking hole into the front passenger side of my door. STRAIGHT through the metal.
The hotel was very apologetic (they ran the valet service, it wasn't third party), and they paid for the full repair of the damage, but I was still pissed.
Not to mention I'm 6'4", and have my seat back a fair amount because of my height. Most times, valets mess with it and change the settings. It's like... don't mess with my settings. Oh, and half of the time I've dealt with valets, they change the radio. It's like, you're going to be driving my car for less than 5 minutes. Don't turn on your music station. Deal with the seat being back and the radio off and just do your job.