I have enjoyed all of it. The series 1-3 era was smart and complex, but occasionally suffered from trying too hard to be oh-so-clever (and succeeding only at coming off as absurdly self-important).
4-5 were rather less layered and far more episodic, but still very entertaining. Series 6 landed somewhere in the middle; with the feel and spirit of 4-5, but with complexity more akin to 1-3.
Intervention Earth and Enemy Lines have been a reboot in all but name, taking on a whole new feel and tone. For my part, I’ve loved them. My one complaint is that I feel like we were deprived of a ‘middle part;’ that IE feels like Part 1 and EL like Part 3, but we weren’t allowed to see (hear) the important events that transpired between.
Regardless—Gallifrey was an excellent range under Gary Russell, and continues to be an excellent range under Scott Handcock and David Llewelyn. I can’t wait to see what they’ve come up with for Time War.
She's more of an alternate Romana who gets proper Romana out of a situation in Series 6, stays around in Series 7, then in Series 8 it turns out something else has happened that makes proper Romana come back and alternate Romana only a possibility again.