I tried opensuse with telepathy and Chakra, both have the same bug with telepathy, when you add a facebook account, user icons are grainy. I installed the latest version with kde 4.11.1 and the problem persists. Reproducible: Always
Facebook only send tiny tiny icons over XMPP. You will get this with any other IM client and Facebook. We do have a plan that sort of fixes this which will allow integrating contact data from other sources which will sort of work round this issue, as we can set the avatar from the data we have in Akonadi that uses their native API. Till then, unless Facebook send us bigger avatars there's not a lot we can do :( Sorry.