I completely agree with you, I have an arriflex 16 bl, and having interchangeable bayonet-mount lenses.. its the best thing in the world...but when im skiing, let me tell you that bringing a red system on a cold snowy day is just a bad idea...especially if i paid for it myself, now if my company paid for it and had insurance, that would be a different story..the other problem is whips and follow focusing, remember, these babies dont have auto-focus...so you're gonna need a whip to follow focus properly, sure its fine if you're doing a shoot from distance standing still....but get into a helicopter and you better be one hell of a cinematographer to pull off some good shots