My cat only eats Purina or Iams. Turns her nose up at anything else. When these are on offer in tesco we buy them because they appear to be in competition with Iams on price so we usually buy whichever happens the cheaper of the two.
A bag lasts our cat about a week but because they are a dry food we have to make sure we give her plenty of water. The smell isn't too strong or off putting, unlike other cat foods I have experienced and they don't make her hyperactive either, unlike other brands.
The packaging is a handy re-sealable blue foil bag. I like this because we keep the cat food under the kitchen sink and have experienced a wet and soggy paper or cardboard box of cat food getting wrecked and having to be chucked out.
Our cat gets about a handful of purina 3 times a day. Her coat remains smooth and glossy so I can only say good things about it. It comes in different flavours if your cat's like ours and into a bit of variety!