As far as the audio tracks, are there major differences between the mono and surround?
Well, obviously, the show wasn't filmed in 5.1...the surround sound audio is a remix of the original mono (and I imagine, probably the introduction of rerecorded audio effects).
As far as being pissed about it not really being the "original" series, how are you surprised, pittrek? You KNEW that the HD remastered series had had new effects introduced, yet you were still requesting that they be captured. Now you hear that they're doing a commercial release of those episodes, and you're pissed.
As has been pointed out, the series is available in good quality on DVD--not even close to the fucked up Star Wars situation. Secondly, the original model effects look like crap--not just the effects themselves, but the film quality. They're grainy and scratchy as hell, from what I recall. You won't get any more quality out of them. The only thing that'll look better in HD is the shots of the actors, so hell, why not throw in some new effects that'll actually look half-way decent in HD, secure in the knowledge that the original effects have been preserved for eternity in good quality on DVD.