There's also an enclosed walkway that runs between all three, the leg between Mandalay and Luxor has some nice shops and restuarants in it. Luxor isn't a bad fallback casino to do a little gaming in, by the way - they've made some nice renovations in the past year plus. Excalibur is still white trash central, however - pass through quickly and don't linger.
The only reason I'd stay in the middle of the Strip is if you intended to spend most of your time there. Cabs in Vegas are insanely expensive, so if you don't like walking and know where you want to spend most of your time, I'd recommend staying nearby. Paris is (or used to be) the best bargain value in the middle of the Strip. As others have noted, there are some sweet deals from the higher-end places right now, though, so explore your options.











