Which area of journalism you're looking to get into should be a factor in deciding which way to go. If newspaper/magazine journalism interests you I don't think you're missing out on anything with the one-year NCTJ course. If you're looking at TV, radio, or some other specialised area then you might require more specific training.
Don't rely too heavily on what I'm saying, though. These are just my experiences and I'm sure you could find someone else that would give you advice to the contrary.
But during my journalism degree I felt that we were wasting a lot of time. And while it does cover more ground (history of the press, foreign and world media, the power & responsibility of the media, ethics etc etc) it didn't seem to me as though there was enough material to fill a whole degree, and we ended up studying a lot of irrelevant sociological and cultural rubbish as well.
You can make it work whichever way you go, so it might just come down to how much you want to go to uni. I didn't need to do a degree because I did the NCTJ straight from A-level. BUt I finished it at 18 and didn't want to start my working life just yet. So I had four more years of the student life, travelling and seeing the world. There's a lot more to uni than just the course you're doing. You meet hundreds of new people, get invovled in activities you would never have done anywhere else. You get the opportunity to study abroad and experience other cultures. And you get loads of free time each year to go and see the world.
My advice to anyone would be to a degree in any subject that interests you... History, English, Politics, French, Biochemistry, Juggling... or whatever. If you're going to be spending three years doing something it makes sense for it to be something you love. And then you can do the one year NCTJ afterwards to prepare you for, and probably get you into, the industry.