Admittedly, i do not have anywhere near enough clamps in my shop. Of the supply I do have, those FSZ clamps and the clamping ellements (MFT-SP) are far and away, the most used clamps in my shop. When used with the MFT tables, there is almost no limit to the uses you can put them to.
i have a WoodRat and I almost never set up there without using the FSZ's. they are extremely strong of grip, yet can be setup to just slide underneath the bits as I slide by for rabbets, dovetails, etc. But when used with the MFT tables, they can be used for everything from first rough cut alignment for ATF sawing all the way thru every operation including sanding and even final assembly.
The FSZ's get used at my flat router table, my bandsaw, drill press and even out in my equipment (landscaping equipment) area upon (very)rare ocasions.
When i consider i use those clamps with nearly every tool and tool station in my shop, i think they are the most used of all of my Festool toys. definitely more than any of my other toys, no matter who made them.
Tinker