I enjoy the second series, less for the sum of its parts and more for some of what it was doing as it went along.
From a creative standpoint the whole thing was bursting with variety and a sense of well-blended fun and drama. The first half of the series in particular remains one of my favourite times in the past decade story-wise. The first four standalone episodes were all incredibly different to each other, and in a good way. We got an alien planet, a historical figure, a contemporary story (complete with classic throwbacks), and a plot-driven period piece. For any flaws any of these episodes had, and all four had them, it was a bold and solid start that felt very strong at the time and still holds up now as a solid run of unique and different stories. Series 7 wanted to be this with its new-idea-every-week but simply didn't compare.
The series actually maintains some very good stories as it goes on. The Cyberman two-parter is decent, at times feeling like a bit of a retread of the Series 1 finale before it, but mostly carrying itself on the strength of good characters. The Idiot's Lantern sits awkwardly on its own, and has a horrendous script in places, but its guest cast is very good at least. The Satan two-parter is superb, and even if the rubber-bogey-in-a-thong ruined it entirely Love & Monsters was an interesting and different concept episode that was bold and actually quite fun until near the end. Fear Her was the first episode that was bad, as in really bad - hard to find redeeming factors it was simply dull to look at, dull to watch. The finale turns things around again though at times feels like a pale imitation of the first series finale - replacing space stations for offices in Cardiff which are passing for Canary Wharf.
So episode-wise the series holds up very well. The problems are more obvious when you look at the series as a whole. The Cybermen for starters, weren't as well received as the Daleks were the year before. And whilst the Daleks were more or less consigned to just two episodes of Series 1 (cliffhanger of Bad Wolf notwithstanding), here the Cybermen are given the run, or the stomp, of four episodes. To make things worse, they're also undermined by the reappearance of the Daleks in the finale which never amounts to a successful stand-off, more than a bitchy natter in the basement. Their two two-parters are so incredibly similar in tone and style that the series as a whole suffers... whereas at least in Series 1 there was an attempt to explore the Daleks from a 21st Century lone Dalek perspective, and a 201st Century Dalek army perspective. These little things matter, as again, the Cybermen were the focus of four episodes here, always in contemporary London - bringing us to the next issue.
It was likely down to financial difficulty and budgetary constraints but Series 2 really begins to suffer in terms of its contemporary London setting later on. The final four episodes are all set in contemporary London, largely on housing estates, not actually doing very much different from each other. To add insult to injury the following Christmas special and the first episode of Series 3 would largely be set in contemporary London as well. It wasn't until Gridlock that we managed to escape London altogether again! Originally Stephen Fry was in place to do a historical episode ahead of the finale but that never came to pass, and so we got a slur of stories all distinctly similar in tone to each other. This is without considering that School Reunion, the Cybermen two-parter and to some extent The Idiot's Lantern had already covered this look. For a show all about time and space travel, it was grounded for far too long.
Perhaps the biggest problem though was the lead characters. Rose felt as regenerated as the Doctor in places, and it didn't feel like natural character development. The romance of the two was played in such a way that it was full of gurning, smug moments and bitchy retorts that made the whole thing feel a bit more domestic. Series 1 pointed and laughed at anything domestic, but the second series just gave in to it entirely. Tennant, though not a bad actor, remains my least favourite Doctor in the role since 2005. His Doctor was too plain, too human... rather vanilla. It missed the point entirely, and the romance with Rose highlights that massively. It was a far cry from the more mysterious Eccleston, who was sorely missed at this point. It didn't help that Tennant spent his first story tucked up in bed, his second body swapping with Cassandra, his third 'putting on' a Scottish accent throughout, his fourth harking back to Classic Who, his fifth having a standalone romance with Madame de Pompadour and so on. Everything was at odds, conflicting with any sense of coherent character - there was a distinct lack of consistency to him early on that didn't play as 'finding himself' but played more like the writers weren't so sure what to do with him, and even more so a case of Tennant not quite knowing how to play him. I feel if you're a huge fan of the Tenth Doctor then Series 2 is riddled with nostalgic moments and promise that you've still got a lot of him to come. For those less won over, or for those missing the Ninth Doctor (which I did, but not to a point I was hung up on it) or for those who didn't like the romantic slant it is a series that isn't remembered as fondly, and in terms of its budgetary constraints limiting it to London suburbs so incredibly often it's the series out of the nine that I currently think is going to date the worst.