I think it's just best to feed what your cat likes isn't it. It seems some are happy with Purina and some are not, I think everything is like that, People have different experiences with different things. That's just life.
Sunny eats 99% dry (usually picks at wet food) and I have to admit she likes to have a variety and rarely has the same bag of dry every time. I try to look around for the better brands on offer. At the moment she has the pets at home premium brand of dry food mature light. She's fine with it and it has basically the same ingredients as say the higher costing ones such as IAMS and Purina One, James Wellbeloved etc.
I always go for one with a good meat content ie if it's a chicken flavour the good brands usually have say 27% chicken. These are the ones I try to get.
When I first had them she ate Whiskas dry food cause she really loved it but then I read the ingredients on the back (after reading about dry food in my cat magazine) and it said it only had 7% chicken in it which I thought was rubbish really. She now haves whatever I can find on offer of the better brands and she's fine. She's a total biscuit monster.

Jack however I have tried to give more dry but he hates it, he's my carnivore boy! Lol Though then again he'd eat the carpet if it had a bit of ham on it!