I'm not really sure about crystallography (not my field), but I think it's maybe an issue with expectation management. Everyone is trying to sell the new technology as fix for every field. In reality XFEL experiments do have a lot of overhead associated with them and stuff like synchrotron light sources are probably better suited for "everyday" type measurements.

The real breakthroughs that I was talking about are for time resolved and "diffract before destroy" experiments for delicate samples. Those ones can't really be done at a synchrotron with long bunches.

I'm especially excited for femtosecond time resolved measurements of chemical reactions. It's going to be so cool to watch chemical reactions occur at an atomic scale.

I guess the other cool application is that there is so much light that you can perform diffraction off of single molecules when you want your sample in solution/gas phase or can't form crystals. Correct me if I'm wrong, but my impression was that the intensity of XFELs also enabled that.