I've rented from them twice last summer, once to check out the Canon 300 f/4 lens to see if I would likee it and I also tried the 70-200 mm. Had a very good experience with them and would rent again from them. The lens comes well packed and ins. has a prepaid shipping pkg. that all you have to do is pkg up and drop off at the PO. Your rental doesn't start until the day you receive the lens. They even e-mail you when the lens is returned.
Sign up for there e-mails to notify you when a lens you want comes in, but the best way is to check several times a day, esp. in the afternoon because the lens don't stay in stock very long, only mins. sometimes, I would also pre. reg. with them because the first time I went to rent from them, by the time I filled in all my shipping and billing info someone else had rented the lens I wanted. They also have a sign up to buy there old lenes, they had a sale last week, some good buys, but didn't have the money to buy one.