Most people I've talked to in Custodial say its really not that bad. They basically work at their own leasure and pace, get frequent breaks, and are always walking around, able to interact with guests, where as everyone else has to stay at their resturant/store/attraction.
I feel sorry for anyone in Quick Service Foods. You either work outside or work in a hot kitchen, you can't make any magic because no guests care about anything at the counter other than getting their food as quickly as possible.
One thing, though, since custodial and quick service foods are the hardest to get people to do, the pay is slightly more.
I, personally, also couldn't do parking, but a lot of them say its not that bad. In the end, the people you work with can make or break a less than desirable job.