Brian, I think the general agreement is that the Holgas have a large tolerance, as an engineer would say, in it's associated bits and such. I dont 'spect that NASA has sent many Holgas up on the shuttle, even though they are cheap and reliable, in their own way. I have 2 Holgas, and I use them sparingly and am not surprised when the pics dont come out quite as I had envisioned. If anyone gets good, or usable, pics from them I imagine they are positively astounded. As they said once or twice in an old economics class way back at the university, "Ya gets what ya pays for", and for $20 (more or less) that's what you get.
I wonder if the Holga sales would increase if they made them entirely out of clear plastic. Seriously, they are useful to learn some about 120 film and medium format cameras in general. They are also a hoot!
I hope this helps you.
Paul