I use CardDav to get my Google Contacts on my iPhone, which works great, but I would love it when those contacts were also in sync with iCloud contacts.
Meaning when I add John Doe in Google contacts it will show up in iCloud (eventually) and vice versa when I add Jane Doe in iCloud it will show up in Google contacts.
I've got an iPhone 4S with iOS7 and a MBP with Mavericks.