I own a Platinum Desert Springs II and used to own a Silver Branson Willow Ridge.
If you intend to get a Marriott TS for the absolute lowest possible MF, then Branson is a good move, but you need to understand something - it has literally zero trading power. Silver, Gold, Platinum - it doesn't really matter. You are not going to be able to exchange a 2BR Willow Ridge for a 2BR Hawaii in the summer. What Willow Ridge is great for is to exchange during Flexchange, when all available properties are visible to you. At that point, even a Studio can exchange for a 3BR Maui (assuming one is available).
Desert Springs, on the other hand currently resales for a very low price. You can find a 2BR Platinum on E-bay for around $1200-$2000. The MF for Desert Springs is only about $200 more than Willow Ridge, but a PLATINUM Desert Springs week continues to have great power. The key is that you have to reserve a strong week to offer. We just traded our March 2011 week (2BR) for a 2BR Ko Olina Summer week (which ended up being an ocean view!)
By the way, when I say Desert Spring Villas, I really mean any of; DSV I, DSV II or Shadow Ridge properties. If you buy a PLATINUM week, they are excellent traders. Non-platinum, not so good. These days, the resale premium for a Platinum is extremely small, so there's no reason to opt for non-platinum.
Also, if you are in the market for a Willow Ridge, be aware that getting rid of it can be expensive. Even a platinum has zero dollar value these days. Most sellers arr paying closing costs and sometimes even the first year's MF. So while it may cost you nothing to get, it will cost you quite a bit to let go.
The palm Desert properties still have positive resale value (not much, but some).
EDIT: You asked how hard it is to get a good week at your home resort. If you are persistent and are willing to call in the middle of the night every night for a week, you can get it. You have to understand that everyone else that owns your season probably wants those same good weeks that you do, so you are competing with them. You have to know exactly the day the week you want will be up for grabs and you have to call as soon as the phones open. Doing it online is a losing option.
I will offer one piece of advice - Desert Springs II has some units that are lockoff and some that are not. The lockoffs for desirable weeks are gone within a matter of minutes. These are taken by people who are going to split the unit and exchange both sides. If you are willing to forego the lockoff option and just reserve a straight 2BR, even the good weeks are easily available for many days after they go up for grabs. This will maximize your trading ability with the week as well.
When we started timesharing, we had these elaborate plans of buying the weeks with cheapest MF, splitting every week, and somehow getting three 2BR weeks in Hawaii every summer. We actually got that two years in a row, but it was absolute hell getting those exchanges, and was the cause of much hair loss. Now we always exchange 2BR for 2BR and have zero trouble getting what we want.
Regarding the Marriott points program, I wouldn't buy into it. Back when they were selling weeks, they promised value and stood behind the Marriott name. Since then, they have soiled the name by treating Weeks owners as second class citizens. They stopped performing ROFR, which allowed the value of the Weeks people owned to plummet to nothing. Yet now they want to sell you points that they swear have more value than the weeks that they used to push ever had. If you want to trust them, by all means, be our guest. TUG members know better.
