Disadvantages: rank till you add other tasty stuff
You can't go wrong with tins of these in your cupboards.
I mean students of the world unite! You will need these in your cupboards, I recommend you spend a large amount of your food budget on these at the beginning of term - think of it as an investment that will last, bacuase I guarantee you are going to spend a large amount of your food budget on beer if you are the stereotypical student.
At least with these in the cupboard, they will last until you starve because
a) they are absolutely rank on their own
b) You are a student and you can't be fagged to cook anything that doesn't involve a ready meal, at least not until you run out of money.
So just before you completely run out of money, get yourself some cheap spices and garlic from the local Asian shop and some veg potatoes and onions from your greengrocer. Also stock up on cheap pasta (I mean pasta, not tins of spaghetti hoops)
Chop all the veg small, any root vegs chop not too small and boil till soft enough to bite. Whatever combi of veg you have make sure you fry garlic and onions, then add your cooked veg to this, and pour in your tomatoes and let simmer for about 10 mins.
Then neck it
Oh by the way there is crap loads more you can do with a tin of tomatoes, but students are supposedly the bright ones - work it out for yerself.
Summary: eat well cheaply - a great addition to anything