I'm a really light typist, I find everything heavier than stock browns to be too heavy. I even find reds too heavy, even though the spring is the same/lighter than browns I find that pushing the switch takes more "work" than browns. When I'm tired, newly awoken or something like that, I even sometimes wish that I had springs even lighter than stock browns. I used to use a flat apple keyboard and the ease of pushing the buttons on that is something I've looked for in a mech. The "work" of pushing the button is so light even though I gather the stiffness of the apple board is the same as browns roughly. Because of this I bought 55g & 50g Korean springs (I would've wanted 45g also but they aren't available anywhere) and, while I thought that maybe this was a case of you should be careful what you wish for, I absolutely love them. I like 50g better han 55g so it looks like that the lower I go I like it even more. It seems therefore that I will probably like 45g best (the lightest spring available to my knowledge), hopefully I'll be able to find them somewhere someday!
I put the 50g in some browns blues and reds. I love it in the browns, still hate the reds, and like blues more with the 50g spring in it.
All this said, I'm thinking of modding a mx brown board to 50g gold springs. However, as I've seen not ONE person mention that he uses this light of a spring in his board, I'm asking myself this: is there some bad side of such a light switch that I'm not aware of? Slider recovery doesn't seem to be a problem at least, and I'm planning to lube them if that changes anything.