My wife and I have been religiously watching this show, waiting for the payoff. We watched even though there were some ridiculously pointless plot twists, and some story lines lingered until this past week ... like the writers couldn't find some deeper reason to have them there, but they created them at the start and had to give them a role.
Hiro and Ando keep us wanting more. Syler is potentially a great villain, and I love the fact they keep turning his character upside down to try and generate sympathy. Mohinder helped tie everything together, but they've turned him into a bit player because he doesn't have abilities, which is just a bad play on the writer's part.
The whole thing has been disappointing, often irritating, and now I'm just waiting for it to end. I might give it another season if they somehow find a plausible end for this whole thing. Right now it's like Season 7 of the X-Files -- one big mess.