The discussion about LLC is way off-topic from the Original Poster's question, and in my opinion, belongs in a different thread.
Rosebud5, I own a lot of timeshares, and do worry about special assessments. There are two main factors that I look at regarding assessments. First, is the board owner controlled? If not, then they may not act in the owners' interests. Many management companies get extra money if there is a special assessment, since they get to charge for supervising the renovations. So, if the owners are not in control, the management company may do unnecessary renovations to bring in money. I'm not an expert on the Sheraton Vistana, but I suspect that is what happened there. (By the way, I stayed in an "unrenovated" Sheraton Vistana unit a year ago,a nd I thought it was perfectly fine, with no need for major repairs at all. And I'm quite picky on resorts.)
Secondly, I look at the physical condition of the resort. (if I can't go see it in person, I ask owners, and read the resort's reviews.) Does the resort need major repairs? If so, that's a big red flag. On the other hand, if the resort was recently renovated, that's very reassuring
I also call up the resort and talk to the management people there. I ask flat-out what repairs they think need to be done, and whether they know of any special assessments in the works. I suspect this wouldn't work at large resorts, but at small, owner-controlled resorts, I've generally gotten useful answers.