A servo one isn't..... in fact it is a bloody liability and fails dangerous. I have had 2 fail on me now. When they go, they go without any warning whatsoever. You can be trundling on safe in the knowledge that your system has been fully serviced to the day, the motor whirrs reassuringly and the bike hauls up in short order, even fully laden. Then the next time you pull the brake lever... THERE IS NOTHING, ABSOLUTELY NOTHING, it isn't even poor braking, it goes from working perfectly to ABSOLUTELY NO BRAKES WHATSOEVER in one pull of the lever..... tell me what is safer about that.
Picture this - brand new to me 1150 adventure, tootling along the lanes in the south of france, braking into a corner in beautiful sunshine on gorgeous roads... NOTHING. Pulled the brake then NOWT, absolutely nothing. Shat my pants. Narbonne BMW wanted to keep the bike and fly me home to fly back the week or so after to ride it back home. Nice touch but no ta. So I rode it all the way back from the Med to St Malo without touching the brakes. I really did.
And picture this.
Around 13yrs ago at the BMW factory I asked why they weren't now offering the 1150 GSA with a decent abs but no servo.
I was told their market research didn't warrant it. What a load of bollox.
First job I've done on my last two 1150 SEs was to remove the servos.