I won't go into all the problems with End of Time. Far easier to go into the good points, which were few and far between. As far as Captain Jack, he should have gone away after CoE and stayed gone. For good. Period.

But I did like most of Water of Mars. Despite the magic wand that used to be a sonic screwdriver, and despite the craptastic ending. I agree with trinityvixen, he should have changed his mind at the start or not at all.