Depends on the college/course, how you learn best, how much you already know, what sort of thing you want to do etc etc. I chose not to go and do Music Tech when I left school, because I didnt want to be spending all my time going over stuff I'd already done/could learn on my own (plus at the time more education didnt sound nice!)
When I left school I was already doing bits with music (putting on my own nights, sound engineering, bit of recording etc) so I decided to get straight into work and earn money to put towards what I want to do instead.
Some courses are well worth it, but like other have said, if your purely wanting to produce DnB, then doing 2 years of live recording techniques won't be a huge help, its good, but if its not what you want to do then you might be better off just learning yourself.
Ive decided now that I'm going to start working through the Digidesign training courses when I get a chance, theyre day/week type courses so I can still carry on what I'm doing but work towards being a certified Pro Tools operator in my spare time, but thats because my main interest is recording and mixing down for live music (although I'm getting more and more into the dnb aswel!)
So yea it all depends on what you want to do, to many people pick a course without looking into what it involves.