One caution I would give about researching timeshares on discussion boards. Most of the boards I have read do not have the traffic or the diversity of opinion that you find here on the DIS DVC boards, and they tend to focus on negatives more than positives. Because there may only be small numbers of very vocal critics, many other boards distort the real picture by being focused on concerns of a few which don't apply to your family at all.
Specific to Marriott, a few years ago they began the transition from being weeks-based to a points system. That change is highly controversial for many long-time owners of Marriott, so you will hear a great deal of negative comment about that aspect of Marriott. Although many Marriott owners may not like points, you may be perfectly fine with a points-based system. Without a huge volume of posts like you have here on the DIS, those negative comments may give you a bad impression of the whole system, when in fact, the issue of points may be completely irrelevant to your family.
What might be much more relevant to your family regarding Marriott is the number and location of their resorts, the resort quality, and the cost of ownership and use.
Similar issues can skew the discussions about other systems. For example, Wyndham has a truly sleazy sales organization. They really do; the sales force is a very negative representation of a fine company.
So when you go to a Wyndham board, you will hear a lot of complaints about lying sales personnel. Worse, you may hear that Wyndham (which is headquarted in Orlando) has an "F" rating with the Orlando Better Business Bureau. You might be appalled and not consider Wyndham as a possible alternative. But if you buy resale like you should, the stupid antics of the Wyndham sales weasels are irrelevant to you.
For a guest however, Wyndham resorts are very nice places to stay. Again, the locations, quality, and cost of ownership and use are much more relevant than negative comments -- no matter how accurate -- about sleazy creeps you will never meet.
We didn't start thinking seriously about selling DVC until we started getting 2 and 3 bedroom Marriott trades regularly at some high-end Marriotts. That ruined DVC for us as there is just no comparison for us.
