I prefer file saved in human readable format. This way you can fix broken file by hand, or change existing one to your liking. When I move *.an8 file to the other computer (for reworking in different time and place or rendering it) I often have to open anim8tor files in notepad and change paths to textures.
Broken files are caused by interrupts in saving process, or exporter or software's core faults. Bugs in compression process would add another opportunity to break the file
I've seen and advice for a few times to turn off the compression (if only your hard drive can handle it) just to avoid errors during compression
Sometimes it's like when I see that some glitches are happening during my work I can predict that it can be even worse. The best I can do is to save the work and close the app before something worse can happen. And yes... I've almost lost 3h of my work because of such situation: app crashed, an when I tried to open last manually saved version it crashed again, backup from about 10 minutes before was broken as well. Finally I managed to open and split file in the parts (to avoid further damages) with newer version of app. It's not that backup process was working wrong, it's rather that it was saved at the wrong time when app was working on the edge of internal malfunction and exporter and/or app core couldn't diagnose the problem.
Solution would be implementing internal checking mechanism that could diagnose internal problems and ask to turn off app and save the work in hope that data structure hasn't been hurt yet. Some bigger software packages have such tool, but even this tool can't predict everything and they still occasionally output broken files.
Sorry for giving such a long and tough reading
