Flexibility is not just dependent on the gasket. In fact, it is far more dependent on the plate and the PCB. A half plate made of a very soft material such as polycarbonate or POM with a thin PCB that has flex cuts supported by gaskets barely high enough to prevent the top frame and case from touching will flex fare more than a brass full plate on a thick PCB with no flex cuts and massive gaskets which keep the top frame and case several millimetres apart. The other major point for flexibility is how much room there is in the case for the PCB to flex.

I don't care about any of that. In fact, too much flexibility can be a bit disorienting when trying to type very fast — the OG Portico made me feel like I was typing on jello, which was a very weird sensation (but it did introduce me to gasket mounts and I didn't look back since).

I do care about the sound of the board. I want it to be bass, and not too loud. I don't want it completely muted, just about the same volume as an Apple aluminium keyboard but not that high pitched nonsense you get from that membrane board. For this sound profile I have to necessarily use a board with a plate gasket or a gasketed top mount (e.g. Mode Sonnet) design. I also need to use plenty of sound absorbing material to prevent resonance. Ideally, I want a soldered board so there is no extra "give" between the switch and the PCB like you have in a hotswap.

So, if you ask me what I prefer, I would tell you that I am most excited about solder boards, big brass weights, high density silicon case dampeners, and some type of sound barrier mount system.

To each their own :)