Crippled min. shutter in av (1/250s is the fastest? Canon, you gotta be joking! Hail to ML!)[/
care to explain what you mean with that?
don´t say you believe, that when you shot in AV the 6D will not go to, lets say, 1000/s if it needs to. then you believe a bad 1. april joke or some nikon troll.
but you sure not that silly?!
anyway i really don´t understand what you mean with that and you may mean something entirely different?
1/1000 s would be a higher
shutter speed than 1/250 s, which is the other direction from minimum
The scenario is you're shooting action in Av mode (yes, I know, why would anyone do that, but don't ask, mmmmkay?), and you don't want the camera to drop below a certain shutter speed needed to freeze that action. The 'Min shutter speed in Av' is quite useful for shooting people - in Av mode with Auto ISO, the default behavior is to drop the shutter speed to 1/FL (1/1.6xFL on APS-C), then start raising the ISO. With a wide lens, that means you might get 1/25 s shutter speeds and even 'still' people showing motion blur.
But I think Canon's idea for the setting is shooting people (not action/sports), where 1/250 s is more than sufficient to freeze motion. Faster, you should be in Tv, or if you want to control DoF too, use M. Note that I'm saying that's Canon's idea, not mine. I do sometimes use the shutter speed restriction (different setting than min shutter in Av) on the 1D X to get a 1/500 s min shutter in Av mode. However, that's in a very specific scenario - shooting perched birds in dim light with the 600 II -/+ 1.4xIII, where I want the little bit lower ISO, and the IS means camera shake isn't an issue. But in general, I think 1/250 s is reasonable as a highest min shutter speed.
OTOH, I do think there's a problem with the feature, in that it's either-or. Say you set a min shutter of 1/60 s, which is often enough to freeze typical random motions of people. Great for your 24-70, no blurry people. But if you put on a 200mm lens, it'll still drop the shutter to 1/60 s, and if your lens doesn't have IS, you'll get blur from camera shake instead. I think an implementation where it uses the min shutter setting or 1/FL, whichever is faster, would be better.