We have only used them once, last year, although it was a package we booked. No problems whatsoever. We were looking at using them this year, but managed to get flights from Birmingham instead, and booked the car separately. The only reason we didn't use TCD was because it is Gatwick, and we don't like the airport. Birmingham is closer for us, and works out cheaper because we don't have to stay in a hotel the night before, or pay for parking.
Always found them very helpful. Didn't mind that we rang and asked quite a lot of questions, and added things to the booking. Always confirmed the changes in writing within a few days.
Flight was OK. Food was OK. The only thing that spoilt the flight out to Sanford was DS being sick, but that was nothing to do with TCD.
They also offer early check-in at LBV outlets for the morning you fly back. As our flight was not until 8.00 pm, this was great, as it meant we could get rid of our suitcases, and spend another day in the parks without worrying about luggage being on view in the car (we had a minivan).
No problems, and if they flew from Birmingham or East Midlands Airports, we would use them again.
Hope this helps