Sadly, I'd say I'm the former of those. The worst problem is its pacing. This could have been done in less than half the time, and the filler they add in isn't even interesting.
Other problems include logic jumps. There is nothing special about Jack's blood, it has nothing to do with his normal immortality, andthat fact iseven expressed in the showso why introducing his blood to the blessing would make any difference at all is beyond me. And how Rex became immortal, is just stupidity at work.
Other issues including the unneccessary sexual scenes, did we need to see Jack in bed with a man twice? I know it's past watershed but this was uneccessary, and acomplished nothing plot wise.
Even if this is post-watershed timeslot, and with the normality that torchwood is a more adult show, it is alarming the amount of blood and gore there is in this, most of it unnecessary. (Ie when the burned not quite dead body is being examined, and Jack asks: what happens if we detach the head?)
Several hours, dead ends and acts of violence later and we're still looking at the consequences of the miricle, with no idea as the who's behind this.
Then there are other issues that make little sense. CIA agents are involved, but UNIT are no-where to be found. (I can accept that the Doctor isn't involved, he's spent a grand total of 5 minutes in the present since the Miricle was started)
Several characters don't live up to anything. The families were busy standing around doing nothing, whilst their plans were being wrecked, sounds a bit fishy to me, whilst Jilly Kissinger adds little to nothing to the plot, and Oswald danes did nothing interesting until part 9, aside from becoming the celebrity you love to hate.
The subplot with Gwen's family whilst interesting should have been resolved earlier, it felt odd in the penultimate episode to have the story of Gwen's father rather than the vital moving forward of the plot
Conclusion - set on an interesting premise, this series fails entirely to capitalise on that. Maybe because of poor writing, or because the writers weren't given the freedom to write a compelling story.
I add that a 10-part episode is a stupid idea and very hard to pull off, especially since each part's an hour long, better to have an ongoing plot in the background, whilst concentrating on individual stories