FS-607 booklet finisher vs. FS-520 staple finisher for CPP 550

The upgrade from a FS-520 standard finisher to a FS-607 booklet finisher that adds trifolding and saddle stitching is a surprisingly affordable upgrade, but I won't be using the integrated folding a whole lot (to make it a clear win.) Further I'm wondering if adding the FS-607 would be likely to add enough additional complexity to the finisher that it could end up stopping the machine due to a glitch or breakdown of the higher-end finisher. Anyone share their experience with the FS-607? Should I keep it simple, or go for this neat finishing option? (if not using the saddle stitching option for the majority of our work, is it as robust and error free as the standard finisher, or can advanced options be bypassed if they break before a service call can fix them to keep normal prints rolling?)