I've just bought a Samsung Smart TV and don't have any issues with the picture from my V6, although I do have the issues that others have encountered with the picture and sound being out of sync (to varying extents on different channels, so most likely a software issue). Hoping picture issues don't now start happening...
Virgin have offered to upgrade my box to the 360 (it's a software upgrade, but you do lose any recordings and series links that you have), although having read some of the issues that others have encountered (it doesn't solve the sound syncing issue for starters), I'm holding off doing that.
It's really poor that VM don't seem able to get a grip of these problems 😞