While some seem to have chosen not use a formal rental agreement,
DVC has included language specific to the nature of agreements in Exhibit "F" - paragraph 5 to the Master Deed:
" ... All leasing or rental agreements relating to the use, occupancy and possession of any Vacation Home must be in writing (emphasis added) and must set forth an acknowledgement and consent on the part of the lessee-sublessee-tenant to use, occupy and possess such Vacation Home in conformance and compliance with the provisions of the Condominium Documents and these Condominium Rules and Regulations. ..."
Regardless whether some feel the agreement offers any protection, the fact remains that DVC mentions it's use in the POS and specifically states what it must contain, so I sure can't see any harm in using a rental contract- especially when sample documents are readily available - just like in this thread.
I would (and do) always advise renters to expect/demand a rental contract from the member from whom they will rent.