I have watched the film as well and based upon your statement "... it's better than I could have hoped for ..." your expectations were pretty low.
I was a big fan of the animated series back in the 70's. They used to broadcast it at like 6 AM on a local station and I would wake up early just to watch it (this is before we owned a VCR). I found the film to be tedious, the acting ridiculous (the actors reminded me of WW II kamikazes) and the central point not the story but the special effects.
I don't know why I am surprised/disappointed because the advent of this level of special effects has made it so easy to make bad movies focused solely on those effects and NOT a good story or acting.
You can get only so much for 22 million dollars, as has been reported was the budget for this film - and we're talking about a film that deals with the destruction of Earth and the quest to restore it...
Also with only two hours to cover an overarching plotline that the animated series had around 12 hours to work in... There simply was no way to hit all the great stuff that was in the series - the battle in the asteroid field, the final showdown in the volcanic core of Gamalon...
My expectations were low, as I knew they couldn't match what my memories as a kid were - however I really did enjoy what the TBS crew did....
and the Naoki Sato soundtrack - is excellent!