Cameron is certainly popular relative to Miliband's utterly dire polling numbers, which is what matters.
Not particularly; personal popularity (or otherwise) of party leaders rarely makes much of a difference here for whatever reason. 1945 and 1979 are the most famous demonstrations of this...
I wasn't really speaking electorally so much as in the context of the "is Cameron 'popular'" question in isolation.
I agree with this. Sporting a ~40% approval rating is quite impressive in these dire times. His center-right counterparts in Europe would kill for those numbers.