We used Lending Luxury for my daughter's Homecoming dress and were happy with the process. I do think the pricing to rent is a bit high but it's still so much cheaper than buying a dress. Another great bonus is that you don't have to have the dress cleaned before sending it back, they take care of that for you. Would recommend and we'll probably be using it again for Prom.
I absolutely love Lending Luxury. It's insane to me to even consider paying $600+ for a dress I'll wear once. You can rent a dress for about 1/6th of the actual retail price which is a pretty stellar deal.