He isn't without his faults, but I love his era.
Reintroducing: Many viewers are suspicious of characters, in many cases, rightly so. If The Doctor had been reintroduced as he was: an eccentric character, many viewers would have turned off due to it's preachiness. (I don't find it preachy, but still...) Sure, we got darker Doctors in the mid to the late eighties, but can you imagine anyone willing to reintroduce an icon in that? Davies did, but did it with a good reason: to make the. We see he's a good man who has been sccarred by war, but discover, overall, that he's a good man. Moral? Yes? Good, but affected by events, so that he's not above us and never above judgement.
Guys, The Doctor in love is not new territory. The Third Doctor clearly fancies Jo in The Green Death, Leela and The Doctor have some embarrassing sexual tension between in their stories (for the record, I love Leela), The Doctor and Romana clearly like each other (until the writers, presumbly on JNT's insistance, dropped it). Sexuality also isn't. Zoe's garb in The Mind Robber anyone? Um, and what else are we exactly meant to think when? And let's not forget the painful remark Tom Baker remarks in when he says: "".
Davies's greatest triumph is with the companions. Sure, this isn't new, Ace and Peri being the protype for these characters, but Rose, Donna, Martha and Wilf all feel real and are extremly well developed.
Season finale endings: watching The End of Time I was disapointed in Davies. If we could have a fully satisfying resolution to the story, why couldn't we have had one every year? Why couldn't we have The Doctor detect unusual energy emmisons that seem to coming from him and Rose after they travelled to the parallel world? Okay, I'll give him a bit of credit for the way that The Doctor's hand and Donna did seem to connect, but why the bloody hell did we have bloody.
The messiah Doctor. But in some stories, The Doctor is protrayed as a messiah figure, which is somewhat at odds with Davies more humanised version of the character. Sure, I'd like to think this was part of Davies's masterplan for The Doctor's fall from grace in The Waters of Mars, but re-examining particular episodes. And let's face it, a title like The End of Time does bring images of christ.
I'm an athiest personally, but the swipes at religon were rather immature in my opinion. Daleks worshipping The Supreme as God? Silly and every bit as fanatical as those Davies wishes to oppose. (And yes, this is coming from a bi man)
The Doctor/Rose relationship: A bit creepy, methinks. Rose running off with a fortysomething (but actually eight hundred and eighty ) year old? Can you say, yeech?
Just my two cents.