I haven't used PhotoStory since v1, but one thing that could have been improved was the timing of each photo's duration with respect to the length of an audio file.

In v1, photo durations did not have a high precision (and they might even have been limited to integers only), so it was impossible to precisely sync n number of photos to a song of known duration.

While support for higher-precision data entry would be nice, an option to "fit to audio file" would be much easier (i.e., have PhotoStory automatically compute a fixed duration for each photo such that the video ends in time with the song's ending).

Again, I haven't used the product recently, so these may have already been implemented in later releases.