We just came back from DL on the weekend and had stayed at the Marriott. When we were there, the main hotel tower was closed, as were their main lobby and restaurants due to renos. They told me that they would reopen this week. We stayed in the Oasis tower of the Marriott which was so-so. The shuttle was shared with the Westcoast Anaheim hotel, not the Marriott's own shuttle service. The Hilton, on the other hand, has its own shuttle service.
Both the Hilton and Marriott are walking distance to the main gate. We walked most of the time. Even closer to the main gate is the Portofino Inn and Suites, which looked really nice as well. If we had to do this again, we'd book the Hilton.