What made the original so good was the delicate balance in the way they handled whether he was in a coma, simply insane, or actually really in the past. For example, IIRC, the first thing he saw on the TV was not someone giving a lecture and then devolve into speaking about Sam's medical condition, but of the broadcast sign-off plate image "talking" to him, this put forth the idea that he might just be insane. ABC has seemed to skip over that possibility already.
IMO, the ABC version has already tipped the scales, possibly irreparably towards Sam being in a coma. In the original, even at the end, you truly never really know what the "truth" is, as the end really could be the beginning. But that was secondary to the path taken to reach the end, the confusion, the uncertainty of being of stable mind, the culture clashes between present and past/future, and how things happening in Sam's "past" are linked to his future are all what made the original so good.
As I've said before, the original was near perfect TV, so the idea that ABC could re-do it, and have it anywhere near as good, would be an extremely tall order to fill.
I'd be interested in reading what the writers of this version are thinking and planning for this show. I think it's quite possible that this version has been "dumbed down" for American audiences, but in the process they've ruined the story. I'd really like to see comments from the writers of the original regarding their take on the ABC version.
In my opinion, watch the DVD set of the original - it will be some of the best TV you've ever seen - and spend this hour on Thursday nights watching something else.