Well, I now have one of each, so I'm pretty happy with my position. The U9BL sees more use than the SPOS MX ever saw, but the SPOS MX invariably travels when I do.
However, you traded an off-the-shelf mass-produced product for a rare collectible single-run Cherry keyboard, with an unparalleled Cherry brown touch-and-feel. I'm unwilling to concede you traded down. Even if the first SPOS MX was discovered at $25, I had to pay more than twice discovery price for the one you now own, and I'm going to be totally unsurprised when the next SPOS MX sold goes for 4× discovery price.
My only SPOS MX regret is that the unit stolen from my car is unlikely ever to be appreciated.