Its not just about dmg, its also tele speed

you have to consider monsters life and verify if this 3,7% increased dps will really help you or not.
Beside this, as stated it's also a matter of movement, that's why 125 is really superior

Over the course of 2000 runs at 7 mins per run 3.7% more dps saves ~500 minutes(rough estimate) not counting the extra frames saved by teleporting faster

This is a weak logic. As I already told, you should weight the calculation on monster health to verify to see how really the increased dps will affect you. On the other hand you can calculate the time saved during tele

125> for hammers, tele etc. in pvp and in pvm.

Its still logic(math). I don't really care how weak it is just need some sense of reason behind having 125fcr - honestly its feels much faster overall due to telespeed so I could suggest that overall the entire run is at LEAST 3.7% faster. So throwing that into a simple equation

2000 runs x 7 mins = 14000 mins
1% of 14000 is 140
140*x = y
x is percent faster per run
y is time saved per 2k runs

140*3.7 = 518 mins

Honestly it is weak logic it doesn't take into account any other variables. However, it suits my purpose.
125 fcr is best

I don't think anyone here need an explanation, you were the only one with doubt about 75 vs 125 ^^
I'm also sure that games lenght is reduced more than 3,7%, just stated that you shouldn't calculate that way

If your added DPS doesn't increase your kill speed, it's useless. Let's say a monster has 10k hp. If you do 14k or 15k it doesn't matter, it will die in 1 hit anyway. If the monster has 20k hp, he dies in 2 hits anyway, but dies faster with the highest FCR build. You have to take into account the hp of monsters where you farm