They may be similarly priced for some of their rooms/suites, but overall they have quite a range of prices, and the four are pretty different in amenities, size, spiffiness and style:
With the new addition, Banana Beach is by far the largest of the four-- it has some 65 rooms and suites. And it also has about the greatest variation in rates, from under US$70 for an interior unit to pretty expensive four-bedroom units.
As Sandy C notes, Caribbean Villas is unusual in that it has some undeveloped land around it (I assume that when it is sold that land will eventually be developed.)
The Palms is right at the south edge of town, with Banana Beach farthest away (about 1 1/2 miles) and Caribben Villas and Xanadu in between.
Caribbean Villas doesn't have a pool; all the others have pools (Banana Beach has two, though they are in the courtyards).
All are well-managed.
Xanadu, Banana Beach and The Palms are somewhat similar in spiffiness and amenities such as cable TV. Caribbean Villas isn't bad, but perhaps not quite up to the others.
You can't go wrong with any of them, but I guess if I had to make a decision, and assuming that prices for the type of units I was looking for were close, I would choose one of the seafront one-bedroom suites at Banana Beach or one of the units at Xanadu.
--Lan Sluder www.belizefirst.com