It seems to cause trouble with scene files pz3. I have no idea why, just that people who use it find sometimes that the scene wont load.

It may save a little time because the morph data is compressed rather than in a fairly big text file but I have doubts as to how much real time is saved. Also to be fair the scene files are much smaller but you have the external morph files as well.

By all means give it a try, but I would save any important scenes both ways.  Using windows compressed folders or using posers compressed files will save lots of disk space compared to uncompressed scene or figure cr2 files .