I loved my stay Bonnet Creek, and highly recommend it. The location is superb, the units are clean, stylish, and very well equipped. The newer buildings have flat-screen tvs, but the older buildings have the better whirlpool tubs.
There are two potential downsides though. It is a pretty dense development---all high-rise buildings of a dozen floors +/- clustered around a lake. I think Vistana is mostly low-rise 3-4 floor buildings, much more spread out, and a bit more lushly landscaped. There also isn't much in the way of restaurants onsite (mostly sandwiches, wraps, pizza), while I think Vistana has at least a couple options. As the Hilton and Waldorf open, things might improve, but I don't have a good sense for how convenient they will be to the timeshare cluster. It probably won't be until the Wyndham hotel opens that this problem is truly solved.
These aren't deal-breakers to me, so personally I'd rather go with Bonnet Creek.
