There seems to be a rather large variance in specific S2 bodies and CR123 lifespans. I know my cam eats up a pair before I've filled 2 256MB CF cards (without any pop-up flash use). And as you know, when they're gone, the cam locks up....most frustrating mid-shoot with a model that's "got it going on".
I know at the workshop I attended recently, one of the guys had a new S2....his died quite rapidly. I just kept going and going.... [img]/ubbthreads/images/graemlins/cool.gif[/img]
Plus, the added weight and length (?) adds tremendously to the balance of the camera. As for the vertical release, it must be an acquired taste. I've used a couple of cams that had them, and didn't like them at all. I prefer to wrap my arm at the wrist along the bottom of the camera for added stability.
As they say, YMMV.... [img]/ubbthreads/images/graemlins/smirk.gif[/img]