to Purrs mrst
If they are eating the wet food, although not loving it, then I would probably persevere with that brand for a while yet. I've tried my cats on a few new foods that they wouldn't even lick (strangely enough the posh ones that cost a fortune!), even a sniff was a step too far for them!
It could be that they just prefer dry over wet so even if they are only eating a pouch each a day it's an improvement over an 100% dry diet. If they're still not tucking in wholeheartedly in a few more weeks then there's no harm in trying some other brands. I know Felix/Whiskas isn't the best quality but millions of cats have lived long and happy lives being fed on them!
If you don't mind buying cat food online then I can recommend Bozita, it's a high meat content food that's presented in a 'normal' cat food style ie brown meaty chunks (my cats won't touch the posh ones that look like chicken/fish!) and is very good value, it costs around £1 a carton which is the equivalent of nearly 4 pouches.
Do they seem to like the Purina dry?