A thought or two, as somebody who has been through most of these systems and taught on a few.
Firstly do a degree because you want a degree - for the challenge, the career options it offers, or from a sheer fascination with the subject. Don't do it as a backup, or because somebody's told you that doing a degree is a good idea, or to keep your parents happy.
All degrees are not equal. For example, whilst the Salford degree mentioned is accredited by the Royal Aeronautical Society (and thus allows you to qualify as a Chartered Engineer), the Leeds degree isn't, and won't. Both are probably fine if you are, say, considering trying to become an airline pilot then using the degree as a basis for moving into technical management, but if you'd like to go into aircraft design only one is likely to be useful.
What's the difference between CPL or ATPL exams and a degree? Just about everything - a degree is about deep understanding of a subject and the ability to use that information to solve problems - it tends to be examined through project work, mathematical examinations, or perhaps by essays - either ongoing or in timed examinations. An ATPL on the other hand is about learning a large amount of material and reproducing it in multiple choice examinations - only a certain amount of calculation is required (for example in navigation) and that tends to be fairly formulaic. This is not to denegrate a tough study task, but the requirements are very different to those for a degree.
Speaking for myself, I have degree level and flying qualifications, and between them find a great deal of job satisfaction (and I'm pretty well paid too!). I think that the engineering qualifications and experience make me a better pilot, and the flying qualifications and experience make me a better aeronautical engineer. However, neither is essential to the other and both were a lot of work if I didn't enjoy them for themselves, rather than just as an add-on.
G