I made (and received after about 20 minutes on hold) my first claim first co.com low fare guarantee refund (>$200) and $100 voucher. Actually ended up with close to $300 refund because they couldn’t match the exact fare Orbitz offered and took me down to an even lower fare.

In addition to having higher fares, co.com did not even display several flight options that were available through other systems.

On the return leg Flying CRP to BOS on a Sunday, I needed to be in BOS by 6p. All co.com offered was a 8:10a departure for >$900. Same flights on Orbitz were in the $700 range. Orbitz also had a 10:15a departure for $35 more than the $700 fare, but that was not even an option on CO.com on either fare or schedual based search. I booked the 10A and claimed the refund and vouchers, but gave up trying to get switched to the 10:15 flight after 20+ minutes on the phone (and getting cut off and miraculously getting the same agent when I called back).