Well I grew up on MST3K, and Teenagers from Outer Space has always been one of my favorite episodes. In fact, I still haven't seen the movie in its original format. So I was always kinda used to it being panned and passing it off as a terrible film. But since learning about the bizarre, but intriguing goings on behind the film; how it came to be made; and about Tom's life and ambitions, I say I have a lot more respect for the film (and interest, which is how I came upon your documentary and website.)
Now I would say it is underappreciated. Unlike a lot of schlock I've seen, the story is basically pretty good - dude comes from cruel, unfeeling planet, meets a girl and learns the value of love, and dude ends up fighting for it. The acting... well, it's not too bad, especially for relatively inexperienced actors. Bryan Pearson really stands out, he was effectively menacing. Sci-Fi is probably the most expensive genre, and trying to do that on a nothing budget, you can really look past a lot of the shortcomings. But the lobster... of all things, why did they choose a lobster?