I can now, I used to go to a big supermarket too for bits and pieces.
They have got better recently, you can get a limited range of spices now and steamed frozen veg packs, when I first went there as a student it was really rough in there and mainly processed stuff so I couldn't wait to start shopping in a big supermarket.
You can't get staples like dried pulses and lentils in there but I imagine, from what I see in other shoppers trolleys, it wouldn't be a big seller. I bulk buy things like that in the world food aisle at big supermarkets anyway so it's relatively cheap.
They do some brands, which I don't approve of because its not meant o be a brand store, but they stock twin packs of coca cola for £1.99 and they stock some of the hovis range of sliced bread.
It all comes down to how brand loyal you are, my dh was raised that brands are best. His sister told me the other day she'd had a supermarket own brand cornetto and it was nice 
as if own brand products are all basically dog poo disguised as food.
I find them very good for cereals, breads, meat, fish and cheese, wine, port, gin, mixers (not an alcoholic), chocolate, baked beans, olive oil and balsamic vinegar, pop, Christmas stollen, crisps, biscuits, fruit and veg. I haven't had any problems with fruit and veg going off but other people have.
Things like garlic bread are cheaper if bought smart price on my way home. They do their own best of both loaf now which is a lot nicer than the hovis one but only 75p.