For someone wanting to rent points to stay or for an owner wanting to rent out points? Assuming the former, so correct me if that isn’t right.
There are two main brokers plus some smaller ones. Brokers do the verification checks on owners so reducing the risk to the renter. It means that if something was to go wrong you would get your money back.
To fulfil your request there needs to be both availability at the resort and an owner who can make that reservation. Room Availability will be the same for everyone. The brokers have different terms for owners and this can affect whether or not they have owners who can book your stay. Which is why it’s hard for a new player to enter the broker market, they need to attract owners who have spare points.
Ultimately the “best” broker for you will be the one who can get you the reservation you want, assuming you’re happy with their terms. Generally you need to go into renting with an expectation of not being able to make changes, and although one of the brokers does offer a cancellation policy it is in the form of a credit.
Currently the brokers are really pushing “confirmed reservations” where owners have already booked the room. Be aware though that sometimes the cost per point ends up being much higher than the traditional way of renting, and in some cases it really is astronomical.
Anyway the two main brokers are DVC Rental Store and David’s Vacation Club.