Cutting down a 6 part story to make it less than an hour long is an immensely tricky task. Here, though, I think that they've just about pulled it off. I should say that it's been a while since I watched the original story, so I can't easily compare what's been cut, but this version does hold up quite well, in my opinion, as a complete story. A few bits, here and there, were a little tricky to follow, and the pacing does suffer, but overall, this works! Genesis of the Daleks is, of course, an incredibly good story, and this version inherits most of that. There's not really anything much left to add. This is good!