My experience (which is minimal--a total of two in each direction...once I rented points TO a friend; another time I rented an existing reservation to a DISBoard poster I didn't know; once I rented points FROM a DISBoard member; and once I had that same DISBoard member transfer points to me)...
I received and paid $10/point 3 of the 4 times; I paid $11/point the fourth time, for the transfer.
I received and paid in full "immediately" all four times--but reservations were made (transfer/name change) at the time we agreed to "do business;" neither the person I rent from or the people I rented to had to wait for reservations while money traveled through the mail/check-clearing process.
In all transactions, I agreed to flexibility if changes turned out to be needed (re-renting, changing dates, etc) but "no refunds" policy applied (I didn't expect a refund, nor did I offer one)...turned out to never be an issue...all four times plans went forward as anticipated so cancellation was never a "real" issue.
I paid and was paid by check. I refuse to even consider using PayPal (have had so many problems w/them--largely involving spam--that I just won't use them anymore). I know the checks I wrote to cover the points I rented/transferred were good. The people who paid me turned out to issue me "good" checks--altho had they bounced I had the ability to cancel the reservation, so I felt "safe."
Finally, my very first foray into renting/transferring, I got scammed...lost $800 (my thread on the experience, "Sad Story" is linked in one of Webmaster Doc's stickies on the R/T Board)...I learned a LOT from that experience (including how wonderful most people in the DIS community are)...but one of the major things I learned is that you just plain have to be willing to take the risk...talk to the people you're considering renting to/from and form an opinion on how smoothly the transaction is likely to go. And then stop worrying about it. Life is full of risks and you either accept the risk in a rental/transfer transaction, or you don't rent/transfer...
Good luck to you! And happy holidays...