I used holidaytaxis all the time in 2009.Never had to wait any more than 30 mins.
On return,they arrive prompt and take you back to airport.I've always been last pickup,
so no complaints there either.
I agree if you want private and want to pay extra,there are other options.
The wait on arrival doesnt bother me,I'd be more concerned if they didnt arrive to get me back
to the airport,and that has never been a problem,so I'm happy with this company.