What if you just buy points?
Since the points program is clearly a hard sell for existing weeks owners, I thought I'd run a couple of scenarios for the real targets: new customers who don't own already.
1. Buy the minimum of 1500 points @ $10/point.
Here you're shelling out $15000. As a company, Marriott can immediately invest that money. If they can't make 5%, then they need new management. But you too can get at least 5% yearly on that money (invested long-term). So, opportunity cost, per year, is at least $750. Maintenance fee will now be $600. $165 all-inclusive fee. Total of $1515. That's $303/night, if you only get five nights (and you will, you will).
In most cases, 1500 points gets a low (mud) season villa for five week nights. A random example: three coastal Florida VCs, whose LOWEST nightly charge is 200 points, with some OK weeks (summer, pretty hot) at 300, but most of the desirable weeks at 500 or more for a weekday 2BR. I looked up charges for May 15-20, five 300 point nights. BeachPlace Towers will rent for $189/night, Ocean Pointe for $239 and Oceana Palms for $349. That's without any discounts (AAA, senior). Put in senior, and the prices drop to $161, 195 and 295. And with a MOD (weeks owner-yeah I know, a bit off topic) discount, even Oceana Palms drops to $227. Only Oceana Palms, without a discount, might possibly make sense, but keep in mind that it's probably the most popular VC in Florida, since it's new. Can you get the days you want on points?
2. Bite the bullet and buy 4600 points, enough (or nearly) to get a high season 2BR week in most VCs. Yearly opportunity cost on $46000 = $2300. Maintenance of $1840. Fee $165. Total = $4305. That's $615/night! $615!
No beach front, no ocean view, no 3BR (at least in Hawaii)! To rent, say Ko Olina, mountainview for July (4575 points) is $484/night, without a discount.
If you have any willingness to consider the time value of money, Marriott Vacation points make no economic sense whatsoever. You end up paying more for the weeks than you would simply buying direct from Marriott. Your "flexibility" depends on snagging the days/weeks you want, with no guarantee they'll be available. If you buy direct, then you know immediately what's available and plan accordingly.
Also, what happens if you want to sell your points later on? What if they drop in value, as has always been the case with traditional Marriott timeshares? You can then factor that loss into the nightly cost of your days and weeks, and get totally sick to your stomach.
AND, if you can't sell them, will you also have the maintenance charges hanging on you, just like regular timeshare users? I think so. You might not even be able to give your points away (impossible? Just ask all those guys trying to "sell" their timeshares on Ebay for $1).