Parts removal is a valid point. Not all brake and shifter clamps force you to slide them onto the bars. I run X-0 twist shifters, so I would have to remove the grips to take them off, but haven't had to in the last year +. My Saint brakes have a 2-bolt clamp that allows them be removed w/o having to slide them off the bars.
Take a look at the parts you are running to see if parts removal would even be an issue. Otherwise slippage and grip style would be the predominant factors. My ESIs haven't slipped at all and have taken the abuse of crashes without issue.
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Wut