Bump to a somewhat old topic. I've had a Filco with browns for a few months. I then got a QFR with blues from Amazon and thought the switches were much stiffer than those on my Filco. Only then did I look it up and see that blues have an actuation force of 50g rather than 45g like the browns/reds, contrary to an earlier belief I had that the three had exactly the same force. While I imagine actuation force isn't completely related to the switch stiffness, I still thought the difference that I felt (in both normal typing and full bottoming out) was more than 5g.
[As an aside, when people mod to ergo clears, people usually group blue springs with reds/browns, which has been confusing me. Is "ergo clear" a very subjective term? Or are all of those springs of equal force, with the actual construction of the blue switch adding that extra 5g?].
Anyway, I got another QFR a few weeks back with the code Carter posted, this time with brown switches. But it turns out that despite using the same color switches, this one is also stiffer than my Filco, and it's causing me to type a bit more slowly and less accurately. Changing keycaps hasn't made a difference, and in fact, pressing down on the naked switches of both boards still reflects the same difference in stiffness. I'm not entirely sure it's a burn in thing since I never remembered my Filco's switches ever being that heavy, but I'm not too sure. So, perhaps it's a difference between the companies that produce the keyboards.
Just wanted to get this out there. Hope others can add to the discussion.