The only time I used II was to trade a week in a WKORV studio for a week at a 2BR unit in the German Alps. The other resort (Sunterra, if I remember correctly) was not nearly as nice, but the location was great, and I got a 2BR for the studio.
You can log in to II and see what they have internationally. There are not a lot of options in many places, but it is a viable option if you want to get out of the ordinary rut.
Lately, I've been finding some really nice places to stay in VRBO.com. I stayed at a place in Rome last October and will stay at another place in Madrid this coming October. Both were very well situated. In Rome, the apartment was block away from the Spanish Steps. No Starwood properties were nearly as well located for exploring the center of Rome.
In Madrid, I actually cancelled a Starpoint reservation at the Westin to stay at the apartment, which is only a couple of blocks away, in the same general area, close to Plaza del Sol, the very center of Madrid. The apartment will cost me about 70 Euros a day (about 1/3 the cost of Rome!), but will be much more comfortable for my wife and I. My Starpoints for the hotel are worth more than that when I need a shorter stay. I much prefer an apartment with a small kitchen than a hotel room, regardless of how nice the hotel is, especially if I'm staying a week or more. In this case, the Madrid stop is the last week of a three week trip, so the washer and drier will be really convenient.
I think for the future, my best alternative, if I will not use all my Maui time or exchange to Princeville or WSJ, is to rent it out, and find something through VRBO. There is a lot of selection there, and no need to wait around for a nice place to show up on II. There are few places in the US worth the exchange through II, and the international destinations are few and far between. With VRBO you can pick something out almost immediately and be ready for your trip in no time. Other people have used AirBnB.com to find a place to stay. I haven't tried that one yet. The few properties I've looked at didn't seem as nice as what you find on VRBO, but that might have been a fluke the one time I looked.