Finally replaced the 10 speed chains on both bikes. KMC says the master link is reusable. SRAM says their link is for one time use.

Kind of vague description for both chains. Does anyone have a ballpark amount of times the KMC link can be reused?
And what makes the SRAM one time use only?

Up until now, I've always used Shimano non-master link chains.

Thanks!