The wife has a 520 with Cyan, as far as I can see most of the upgrade is optional, you can choose three columns, you can choose to have a picture on your tiles, you can choose to swipe or type and I have played about with her phone and it isn't laggy at all.
Bob
Hmm I don't have any of that enabled. I'm glad to hear that you are happy with it.
I guess I'm just one of those unlucky ones. Like how things happened to people upgrading to Black(some had many issues). Or maybe its was third party apps related (I had issues with whatsapp and meander, the apps just wouldn't fire up. By the way thanks for dropping by with the opinion it is very much appreciated.