What is this resort like? - It is a very large resort that caters to a lot of convention and business travel. There is a very nice pool area with water falls and slide, a fitness center/spa, tennis courts, and golf course. Very clean and modern.
How accessible is it to WDW? - There is a shuttle bus available for additional cost. I'm not sure how much or how often, I'm sure other will post. If you'll have a car, I recommend driving because you are right on the main road into WDW and very close to all the parks.
Is it in walking distance to DD? - NO! If you ask for a room facing DD, you can see the DD and most of the evening fireworks, but you definately need to drive, bus, or cab over.
We stayed at MOWC last April on a Priceline bid ($65/night) and had a great time. Staff was nice, pool was excellent, and room/bed was comfortable.
The only drawback was the parking. If you stay in the main tower, there are limited spaces in the front lots and you may have to park in the main garage structure. This is a real hike to and from but they do have a shuttle available. I think valet was about $10 bucks a night but I could be wrong.
Except for that, I highly recommend this Marriotts.
Steve
Jumping back in to add...Try doing a search for MOWC, you should be able to pull alot of previous reviews and info on this resort. Do it one board at a time though or you'll get swamped. Search orlando hotels & budget board first for best results. TTFN