I would have to agree, in re the GF 45-100 F/4. I'd originally purchased that lens for its OIS and my GFX50r, but I'd found the combination to be a tad nose heavy. So I'd transferred the lens to my GFX50s, where it is very happy and will likely be a permanent resident. The GFX50r, however, now has the smallish GF 50mm attached, and it too is a happy camper. My GFX100, on the other hand, can handle just about any lens I hang off of its mount . But, in summary, the GF 45-100 is a fantastic lens, its optics are superb and like you've already indicated can be used down to a 15/s-30/s handheld, with resultant, sharp images. Furthermore, the focal range suits my general needs.