Virgin Media powered by TiVo or Sky+HD?

Hello, this one is more for UK commenter's. But I was just wondering whether anybody would be able to tell me which is the better of the two mainly for ease of use for my Mum. Who doesn't work very well with complicated menu's and would like an easy system that she can understand and doesn't need her to constantly ask me for to help her work it past the first week and a bit.

All suggestions and help is gladly welcomed and thanks in advance.