I am also very interested in this company's reputation. I did some deep searching and found a few reviews on travel sites buried in hotel or airport transportation reviews. The easiest to find is on Trip Advisor. Just put BuyReservations.com in the search box on the upper right of the home page. They are a fairly new player (a bit over a year) but I have not found a single bad review about them. The Chicago Tribune listed them as an affordable alternative resource to the airport parking lots in an article about holiday airport parking this last Christmas travel season.
I was comfortable enough with what I found to reserve a room at the Marriott Courtyard near O'Hare with 14 nights free parking for $89.99 (about $104 after taxes,etc., were added). You can stay the night before OR the night after your trip. We live in NW Indiana serviced by TriState Limo (which is really a bus) to the airport, as well as the South Shore rail that connects to CTS trains to both O'Hare and Midway, but the first train/pickup in the morning was too late to get to the airport in time for our 6:50 AM flight. The fare for two of us on the bus was the same as the park-stay-fly package. I checked the Marriott Courtyard website directly and they charge quite a bit more if you book the stay-park-fly package directly with the hotel, and only include 7 days parking.
If you have a very early or late flight, be sure to check the information on each hotel listed for the time and frequency of the hotel shuttle. I chose the Marriott Courtyard for the14 days included parking because they will provide taxi vouchers if you need transportation when the shuttle is not running. Also be aware that the hotel may need you to make reservations for a specific shuttle time and if you miss it, you may have to either wait for the next run or take a taxi to the airport at YOUR expense.
Also be aware that Buyreservations.com is NOT open 24-7. Our reservation is for check-in at a time they will be closed. I will confirm directly with the Courtyard Marriott before we leave home so we don't have any surprises when we check in.
Buyreservations.com also provides park-stay-cruise packages near cruise ports including Port Canaveral, Tamp, Miami, and Ft Lauderdale.
Hope this was a little helpful!