Macworld November 2004 edition has a short review of iStopMotion and awards it 4 1/2 mice:

iStopMotion takes you beyond the ordinary with its two modes: Stop Motion, where you animate objects incrementally and capture a single frame at a time; and Time Lapse, where a frame is shot at an interval (such as every minute), resulting in sped-up footage of things like clouds rolling by or flowers blooming. [...] The only drawback I encountered was choppy playback when previewing the movie.

This has been fixed in Version 1.5.