Octane is bad because stim only affect his forward speed.
I have tried to use Octane the way i do in titanfall 2. Amd instantly noticed stim only affects his forward speed not his strafe speed.
So Octane stim can not be used to help him dodge bullets.
His problem is he can only use his stim in a straight line.
Octanes stim should increase his mobility in everyway.
Increase his forward and back movement.
Increase his left and right movement.
Increase his jump height by 40%.
If this is OP then decrease his tactical cooldown.
It is better for Octane to have a useful tactical with a longer cooldown,
than useless tactical with a quick cool down.
Increase his stim strafe-speed.