I've watched the UK version of Queer as Folk over the last couple of days. Absolutely loved it. There is so much I could say about the way that this show contextualises RTD's work on Doctor Who and Torchwood, but that would take way too long (and probably lots of other people have already said it) so I'll keep my comments... brief-ish.
Overall, this didn't so much change the way I view RTD's work as it reinforced the views I already held.
For example:
1. RTD is an excellent writer who is at his best when writing character-driven narratives, for characters he has carefully crafted himself. I'd only been watching QaF for a matter of minutes before the characters became people to me. I hurt for them, I felt happy for them, I yelled at them... all of that.
2. As so many others have observed, RTD only seems capable of writing one kind of romantic/sexual relationship: that is, a relationship between Person A, who is hopelessly in love/infatuated with Person B, who is distant/selfish/not heavily invested in Person A. Because RTD is a good writer, he can make this interesting in different ways with different characters, but ultimately, it's the same story over and over again. This is a big limitation on his otherwise excellent character writing.
3. Regarding Torchwood -- and particularly CoE --
QaF only confirms my opinion that Jack didn't really care for Ianto in a personal way. I know that, in keeping with point 2 above, I've seen people comparing Jack/Ianto to Stuart/Vince (I can't remember who, or I'd acknowledge them), arguing that Jack's attitude to Ianto in CoE can be explained by seeing him as a Stuart-type character. I disagree. While both of these pairings do conform to the above pattern, in Stuart's case, we are not left in any doubt that he does, in fact, care for Vince. True, he cares for him in a very selfish and fucked up way, and in so many ways Vince would be better off without him, but in spite of that, there is never a single moment where we doubt that Stuart has a personal investment in Vince (and indeed, that personal investment leads him to do some of the most fucked up shit that he does, particuarly regarding the Vince/Cameron relationship which AGAIN conforms to the above pattern, though with Vince in the selfish/distant role). I know a lot of people see Jack's response to Ianto's death as evidence of a personal investment, but honestly, when it's contextualised by the first three episodes of CoE -- to me it just looks like an expression guilt that he didn't care for Ianto in that way. RTD is a good enough writer that, if he'd wanted to show that Jack cared for Ianto in a personal way, he would have been able to show it in Day One and Day Three, while still making Jack distant/selfish/etc -- the fact that he DIDN'T show it, says to me that he didn't intend to do it at all.
And I do think it was an extremely poor choice on RTD's part to (un)develop J/I in this way, all the moreso now that I've seen QaF, which is why I like reading denial-J/I fic that develops their relationship in different ways, and why
I like writing it too. But I'm not going to be in denial about the fact that it is, indeed, denial fic, no matter how canon-compliant it is in a plot-sense. (I'm also not going to deny that my non-denial fic is probably better than my denial fic -- I'm not sure what that means for me.)
4. Folding back in to point 1, this is exactly why I'm still not sure if I want to watch TW S4, if it happens. It's not because I think RTD is a bad writer (even though I think that some parts of CoE were badly written), it's because I think he is indeed a fine writer -- becasue I KNOW he will create new characters that I can love. In a show like QaF, loving his characters is relatively safe -- he hurts them, certainly, in heartbreaking ways, but ultimately he rewards you for loving them. In Torchwood, he's made it clear that you get punished for loving his characters (and he expects us to be happy about it). And I don't want that. (Although, I have heard that apparently RTD wanted to give QaF a sad ending, but the network wouldn't let him, which is why he did the over-the-top happy ending instead -- can anyone confirm/deny this?)
5. Anyone who says that RTD doesn't understand homophobia is a douche. A big douche-y douche. (Which is different, of course, to critiquing the texts he produces in terms of whether or not they conform to narrative patterns/tropes that are often used to reinforce homophobic ideas.)