Is it worth the extra money?
Oh yeah for sure! It's beautiful what they've done with it. They've cleaned the prints up real nice and the remastered effects are done tastefully.
I think most of the episodes were shot on standard 16mm, meaning that the negatives are probably pretty crappy by now.
Well try and find a 1080p torrent of one of the episode and see for yourself. Personally I think they look pretty damn good.
Just to note, they have the remastered video with new cgi effects & 7.1 dts-HD Master audio, and remastered video with original effects and original audio. So no one is missing out on either one there. You can flip between each one with the angle button while you are watching them.