Isn't Jack just basically another version of Ten just with more sexin' these days? Maybe that's why he's lost his sheen for me since I can't say I'm a big fan of Ten either. He's just another version of the angst-ridden 'lonely god' "nobody knows the troubles I've seen" trope RTD seems fond of except instead of sacrificing his 'people' he gets to sacrifice various relatives for the greater good while stoically suffering in his loneliness (or not) because no-one understands how lonely it is at the top having to be the immortal anti-hero all the time.

I wouldn't have minded if they'd stuck with a s1 Who version of Jack for Torchwood since I think that was probably the best version of him, but if they went back to that version after the events of COE I probably would end up hating him and despite the show's best efforts I'd rather retain at least a little bit of fondness for Jack.