It's a real snare drummer's snare for sure.
Chromeo!
I thought you did a very nice job on the A/B comparison between the two different model snare drums! That said, I'd like to add this ...
I actually play/gig BOTH these models on a steady basis. I will say/agree that both demand at the very least, a modicum of technique as neither model will let one "hide" or "fluff" through anything as EVERY STROKE played is heard as clear as day! However!, there are ways to slightly "tame" the Fibes SFT 690 through different head choice! What I have found .. for me, as this is completely personal and subjective .. is to go with a slightly heavier batter on the Fibes. In this case, a REMO Emperor Vintage Coated. That head ever so slightly knocks down that super high end snare sound, yet is thin enough for excellent brush response without issue! I play both models wide open, never any dampening. Resonant side is exactly as you have on yours, a REMO Ambassador weight hazy. I gigged my 1967/68 Fibes SFT 690/COF all last year with this set up in all kinds of venues with nary a problem ... and the beauty is ... the projection of fiberglass!, but again, slightly softened with that head combination. You might try that on your Fibes! Here are a couple pics of the drum I was talking about!