So, I went for M4 and RCS 19 Corsa Corta. This is the result:
Besides, I have a friend who got SX SE Plus model , purchased it in 19 ( mine is base SX 18) and he got same stock Nissin master cylinder as I did have and he got Stylema calipers + reinforced brake lines. So, we did compare performance/feelings before my Brembo swap and after.
Before : plus/minus same performance (stopping power) being not so much stupid going far too fast for tests. Both noticed longer brake lever travel on his SEPlus. Some like it, but not me.
After : Mine was better initial bite ( I guess pads going into factory ALWAYS worse then same pads purchased from pads manufacture because of price pressure from OEM) and almost zero free play at lever, which I was targeting. And, which is also important, my setup gives constant brake feel from high speed , say from 200+ km/h to almost full stop.
At the time of the test I recalled my zx14r performance sport ( Brembo + Brembo stock) which was equipped with so bad pads from stock, that one single hard braking from 240 to almost zero gives a smoke coming from pads and giant back pressure from brake lever that I almost never felt before. Changing pads into Ferodo Performance Series gives me totally different picture. So, I guess someone who is not satisfied with Brembos on their SE and upwards models - go and buy good pads from Brembo / Ferodo first.
P.S. The best ever stock brakes I noticed from my all time experience was R6, 2019. No free play, sharp but adequate initial bite, pretty pretty constant feel and back pressure. Nissin/Advics by the way.
