Since leaving Oxford and getting back to the real world, I've had the chance to talk to a number of people from the training departments of numerous airlines. The general feeling is that whilst it used to be the case that airlines preferred graduates from the CAP509 schools, JAR-FCL has changed all that. An increasing number of airlines, notably BRAL, have made it known that they will not even consider graduates from integrated courses. Training staff have found that such pilots have been trained only to pass the IRT in a light twin and have little or no grounding in the basic skills of operating an aircraft. It now takes more training to put an integrated student on line than it does a modular student.
To be fair to the integrated schools, if you have only 75% of the training time, you can produce only 75% of the pilot. Under CAP509 the minimum flight training time was 200 hours, under JAR-FCL it can be as little as 140 hours. It is notable that OATS have found it necessary to offer a longer course (at an increased price) and that ATP Academy see a market for an 'advanced' course. BA now (suspension of training aside) put their cadets through a 'Jet Orientation Course' which was not deemed necessary in the CAP509 days.
The word on the streets seems to be that a CPL and IR gained through the modular route, along with some meaningful experience, is nowadays worth a lot more, in the airlines' eyes, than the same qualifications gained through the integrated route.