My DS did one. I won't cover the advantages except to say he wouldn't have had it any other way. Loved his time and is still working for his employer and has had a lot of promotion in the 7 years since he started.
........ but it was disadvantages that were requested:
Difficult to get an offer. Each application is different and takes a lot of work for a small chance of success.
A need to be independent from day one and have to arrange your own accommodation etc often in professional houseshares with older adults. The lack of hand holding and helpful supply of information might be seen as a disadvantage by some.
You study with a small group and everyone is interested in the one subject. It might be seen as an advantage to be mixing with many more students with different interests with a traditional Uni degree.
Your work and study alongside limit time for socialising.
You will have a degree from a Uni that supports your employers course not one you choose.
Depending on how the degree is delivered you might have more limited access to the Unis facilities.
(In reply to the poster worried about the low ranking Uni and not being competitive later on - an apprentice will have work experience and that will place them differently in applying for jobs than a graduate out of Uni. Additionally the skills most apprentices need to just nail a position will also probably put them in a good position when being interviewed). Much depends on the employer the apprenticeship is with.