For my own plugins, I only release 1.0 when I feel it's as perfect as I can make it, and subsequent releases will add functionality. Of course, there's always bugfixes, but *ideally*, 1.0 is bug-free. I will never release something when I *know* it contains bugs.

For larger/trusted/established brands, they can get away with releases that contain bugs (and use the "release early, iterate often" method), but this often has to do with a hard deadline. Sidekick's decision surprises me, but it's understandable. The examples they give speak for themselves.

Finally there's also the matter of "unfinished" vs. "buggy" -- it's not nearly as bad to release software that has some functionality modules that are not ready for use yet, than to release something that doesn't work as intended.

Factors that I didn't address here; money/price (commercial software), reputation and liability. Those also have an impact on delay/cancel/release decisions....(irrelevant to most small, homebrewed plugins).