jamyskis: Hmm...I dunno. I find that the best remakes sit in a sweet spot between those two definitions. A complete 1:1 remake is fairly pointless in my eyes, as then you might as well just bundle a pre-configured emulator. It's precisely what GOG does with DOSBox and ScummVM. I don't really go much on all these 'reimaginings', but a good remake should be able to precisely replicate the original experience and build upon it. A great example of this was the two Monkey Island remakes. Baldur's Gate EE, on the other hand, was a badly missed opportunity.
I am liking what Bitmap Bros have done with this though so far. Will certainly be picking it up day one off GOG, and may even get it cheap some time off Steam as well (as in, VERY cheap).
I agree with you in a way, I think this Chaos Engine remake could of done with some more levels and perhaps an extra class, I just think a remake should if possible use the original assets and code to preserve the original game, BGEE did this but it was a sloppy job aimed at tablets, and it's actually worse than the original games (with mods), so not really comparable.
I just find the claim that a remake can be faithful without access to the source-code and/or a programmer who personally worked on the original, or at least a dis-assembly of the game, quite outrageous. How can developers remake a game if they had no idea what was going on under the hood in the game's logic? Without that the best developers can do is clone the game based on how it plays, or as you mentioned the dubious "reimaginings" which are just entirely new games.