I doubt you'll get many responses on this forum - you'd likely get more in exchanging or on the Marriott board. You can ask the moderator to move this, but should not start another thread yourself as duplicate threads are frowned upon.
I'll give you my two cents - the CI is directly across the road from the two Marriott Desert Springs Villas, so in terms of location there is no difference. It depends primarily on what you like in terms of atmosphere. CI is small, all two story buildings arranged in several clusters around pools. Very desert-like grounds, and architecture that blends in with that. Not much else there (which is why I prefer it). The Marriotts are larger developments with tons of units, located next to a hotel with several restaurants, in a much more lush and oasis-like atmosphere.
There are lots of reviews on these and other Palm Desert resorts here available to members.