We stayed at the Courtyard last August with the discounted rates, and liked it so well DH and I are again celebrating our anniversary there. We did not rent a car for that trip, and will probably not rent one in Aug either. We did an E-night, but did wait a long time for the Downtown Disney Hotels bus to arrive after e-night. The bus picks you up at the TTC, not in front of MK. Downtown Disney Hotels transportation is scheduled, running roughly every half hour to the parks. The transpo to the water parks occurs less frequently--maybe twice in the am, and once early afternoon, and late afternoon for return. If you have a multi-day pass you are entitled to use Disney buses. We would catch a bus to Downtown Disney (after a meal, or whatever) and walk (for us 15 minutes) from the Disney bus stop to the Courtyard. The Downtown Disney Hotel buses are more comfortable than the regular Disney buses, but do stop at all the hotels. Courtyard is usually the 2nd stop, had no trouble getting seats, compared to Disney transportation.
I did miss being able to run to Publix, but lived without it.