The self parking is on the south end of the casino whereas the check in desk is at the north end. They are essentially as far apart and they could possibly be. However, I don't find the walk too bad as the connection from the garage to the casino is fairly close....certainly closer than MGM. At least in this way you are in the A/C while schleping yourself and your bags to the check in area. I'm guessing that from the parking garage to the front desk is about a five minute or less walk. There is a tiled walkway for the entire path once you enter the casino so little resistance on your wheeled luggage and no having to dodge machine players, chairs, etc. on your route.
The valet system is pretty good in that you can call ahead from your room to have your car brought up. In the same way as the self parking garage, the valet pick up is at the south end of the casino.
If you opt for self parking, enter the garage and go up one level. This actually puts you on the same level as you'd enter the casino and take an escalator down. This is better than having to wait for an elevator in the garage. Parking always seemed pretty plentiful the last few times I've used it.
Dan