Tactile stemsTactile stem comparison by jk_pens.
Opening up a bunch of tactile switches to make some frankenswitches, jk_pens used digital calipers to measure the stems.
Specifically, I measured the difference between the deepest "trough" in the tactile leg and the "peak". This represents the maximum distance the tactile leaf spring is depressed when the key is pressed.
A picture to help understand what is being measured: https://imgur.com/gallery/tn8nBUY
Perhaps unsurprisingly, both Cherry MX and Gateron browns came out at the bottom of the ranking by this measure.
On top of that, some experiments I did with swapping in more tactile stems confirm that the brown switches also have relatively weak tactile leaf springs. For example, a Polia stem in a Gateron brown is more tactile than the stock brown, but not as tactile as the same stem in a U4T housing.
Note that the differences in tactile leaf springs and other factors such as the shape of the tactile leg mean that this ranking by itself may not give you an accurate assessment of the overall tactility of any of these switches.