I have used Advantage but not in Orlando. I didn't have any problems with them. Car was fairly new and in great shape.
I used them for a one way rental from RDU to BOS. They were at least $100 cheaper than anyone else.
If you decide to rent from them, be aware that if you want to use a debit card, they run a credit check and if you don't pass their criteria, you can't rent from them. It's not an issue with a credit card.