I remember watching this show when I was younger (2nd-3rd grade) and have to say that I didn't get it then...i'll give it that I was a little young, but I think that that was the core problem. TTP needed an audience that could understand what was going on a little more than a typical Nickelodeon audience could. I recently saw the five-part Pilot Ep again, and while there were a few guns drawn, none were fired. Even while I was watching it, I was saying to myself, 'this is/was a Nick show - no one can die'. took some of the suspense out of it. At the same time, they had the bumbling scientist trying to catch them. This was the formula of a number of Nick Sci-Fi shows, Alex Mack and Allen Strange being two that jump out. Maybe I can't blame Nickelodeon for this 'cuz the BBC produced it (I think - def wasn't stateside).
Many people have stated that the 70's version was the better of the two series. maybe 'the vanishing earth' was a poor example, or maybe it was so painfully 70's that it was distracting, but no matter which way you slice it the original TTP episode I saw was a bit...noncontiguous. they seemed to jump around alot and made it difficult to figure out who was doing what - it seemed overcomplicated and a bit drawn out (think 2001: a space odyssey).
Anywho, I def liked the show and would like to see more eps of it...maybe an '06 reboot? worth getting the DVD set if you grab 'em at a good price!