I loved ten to begin with, the speech he gives in The Christmas Invasion before pushing the button is probably my favourite DW speech ever and DT delivers it perfectly. I however really don't like the change in direction that RTD took the show with the companions and how the Doctor becomes almost god like. I can't fault the writing or acting as in the main it would be fantastic if it wasn't for the fact that it is meant to be Doctor Who not a soap opera.
I also enjoyed The Christmas Invasion and I thought I was going to like Ten based on what I saw there. Alas.