Grand Desert, LV, the Washington DC resort and many more are all at or above Marriott quality and Marriott's nearly across the board are of higher quality than
DVC tends to be. QUOTE]
Our family has stayed at Grand Desert, and it is not anywhere near the quality of DVC resorts. The furnishings are much lower quality, the pools are lower quality (no water features, and maintenance was seriously wanting,) security was below lax, and the clientele was, as another poster asserted, much less...careful...about such issues as dress, grooming, language, public intoxication, etc. (From our room, we observed a group of young adults playing a drinking game involving urinating into the pool, which, even after we called security, went on for over an hour!

)
We resolved never to go back to Grand Desert, and stick with the HGVC on the Strip (which definitely IS comparable in quality to a DVC) and/or Marriott's Grande Chateau (which we love when it's just DH and me, but not for the kids, as the pool there isn't good for the kids.) We also own two Marriott weeks, and so far our experiences with Marriotts have all been good--definitley similar in amenities and quality (but of course no "magical" theming) when compared to the DVC properties.
I guess what I'm saying is that with DVC taking away my ability to trade out to Marriotts and saying , "Here, you can trade into Wyndhams now!" I'm pretty unhappy.