We rented one that I think was a 5 bedroom. This particular home had prices based on how many rooms you needed (or how many people you had), and they basically just locked the doors to the bedrooms that we didn't pay for.
From our fairly limited experience (a couple rentals, and quite a bit of searching), most of the listings on both VRBO and HomeAway had cleaning fees and other charges. By the time we added all the charges, most of the time it just wasn't worth it to us (thus quite a bit of searching but just a couple rentals!).
You also have to keep in mind that they are rental homes rather than timeshares. You'll likely have a real hodge podge in the kitchen (often better than a timeshare). You'll have no organized activities. You'll have no mid-week cleaning. Sometimes you'll have to provide your own linens, toilet paper, towels, etc. It's much less consistent than a timeshare. They typically don't take credit cards. And if you have maintenance issues, it's not like they can move you to another unit. We had maintenance issues several times with one rental (A/C kept going out, in summer). They were slow to get it looked at. The maintenance man came out twice and it was never fixed during our stay. And they didn't refund any of our money. We had paid with a check, so we had no leverage to encourage them to make things right.
Still, it's a good alternative, especially if there's not a timeshare in the area.
