I rented a compact from them for 9 days for $173. We got to the airport and I called them for pickup. They were there within about 5 minutes. The shuttle also said Ace Car rental. It took about 10 min to get to the rental place which turns out is Florida Car Rentals. Ace and Continental share the same building. I got waited on right away and was not given any hassle about insurance when I declined it. I was hoping for an upgrade, but we had our choice of a Ford Escort or one of the Korean cars(I had test driven these and did not like them so I picked the Escort). I was told to check the car for scratches and there were quite a few so I marked this on the sheet. We went to leave and the 'check engine' light was on, so we went back in. The guy said it was probably not a problem and that I could take the other car. i opted to keep the Escort because I have driven in cars with that light on without any problems in the past. I marked that on the sheet and he assured me that they would get me a new car if I had any problems. We did not.
This was not a luxury car. I think it had about 40K miles on it. We fit 2 adults and a 5, 8 and 14 year old in the car. Our luggage all fit in the truck, but I did not pack heavily.
Return- we were a little late, but again, I was waited on right away. I did not run into any problems. The shuttle was supposed to run every 10 minutes, but it was or seemed longer because I was in a panic about getting to the airport on time. We ended up getting there about an hour before our flight which was plenty of time.
I have checked my credit cards and have not found any charges from Continental on there, so, so far so good.
So, if you want to save some money- they are fine, but if you are picky, I would not go with them.