I will take a shot to add a few items:
1. DVC points is tied to a specific resort; as a Home Resort Priority - Marriott is not tied to a specific home resort. Instead, you own shares in the Marriott Trust - with 250 points being a share (forget the actual term for a share right now - sorry).
2. DVC allows home resort booking at 11 months out - and then 7 months out to any other DVC resort in the system. I need help on the Marriott side, but I believe it is something like 12 months out to book 7 days for regular owners - 13 months out for premiere owners to book 7 days - and 13 months for Premiere Plus owners who can book less than 7 days. I am probably wrong somewhere in here, but someone can correct me.
3. DVC dues ranges from above $4.00 per point to around $5.00 per point, depending on the resort you own. Marriott is at $0.40 per point - but DVC uses less points. A minimum DVC buy in is 150 points, and Marriott (for non-weeks owners) is 1,500 - so they are very similar.
4. DVC used to heavily discount week days, and charged double or more for Friday and Saturday night. At least at the resort I own, that has changed recently. DVC now has leveled that off so the Fri/Sat night points are very close to week day points. Marriott is starting off like DVC did, with Fri/Sat being much higher, giving great values for Sun to Thurs stays. My guess is this will change in the future.
5. Both systems you must call in to make a reservation - no on line access.
6. DVC has several resorts around Disneyworld, which are fantastic if you are going to the parks. They also have Vero Beach, Hilton Head, Disneyland, and next year will open up Hawaii, down the block from Marriott's Ko Olina. Marriott has far more properties than DVC - so a plus to Marriott on this one.
7. You can use DVC points for cruises, exchanges to RCI and other Disney Vacation trips. Marriott has a similar thing, difference is exchange company is II instead of RCI.
8. DVC does not charge you an annual membership fee to use your points (trade) to stay at other DVC resorts, use RCI, cruises, destination trips etc. Marriott is charging $165 per year for 1 week, and $199 per year for multiple weeks. Not sure what the fee is if you are a straight points owner, so maybe this does not apply. Again though, DVC does not have a charge.
9. Resort qualities vary - the older the resort, the theming may not be as current as a newer resort - which is true in DVC and Marriott. Generally, I think Marriott has some better space in their units then DVC. I believe all DVC 1 bedroom or larger has a full kitchen (regular sized fridge, stove, etc.). My Maui Marriott does not have a full kitchen.
10. DVC points to stay at older units are less than staying at the new ones. A week in Hawaii or at Disneyland is a lot more points than the older resorts in Florida. According to the Marriott point chart, that is true for Marriott as well, so they are similar. With each new DVC resort, the cost of points goes up, and the number needed seems to go up. My guess is Marriott will be doing the exact same thing.
11. Resales - If you buy DVC as a resale, you have 100% full benefits just as if you purchased directly from DVC. I have done both so I know this to be a fact. Marriott is fine with telling potential points buyers that the new owner on a resale may not be able to join the system (maybe it is "will not" be able to join, but I am not 100% sure).
12. DVC is active in ROFR, and the points at my resort I bought many years ago, are still selling for what I paid for them. If it dips too low, DVC snatches them up and resells them for a profit (very, very smart in my opinion). Keeps my resale values high if I ever need to get out. Marriott is unknown at this point what they will do with a points person who wants out.
13. DVC is Right To Use - meaning you give it back to DVC at a certain point, usually 50 years from resort build date. Mine goes back to them in 2042 I believe. Marriott you own a piece of the Trust. I assume for life, but I am not a trust attorney so i have no idea what the ownership really means, and if my heirs will be able to take over my points, or be locked out like a resale buyer.
That is it for now - but i am sure I have a ton more if you ask a question to jog my memory