Dear lord, been looking at screen passes a lot today and there is just so much wrong going on I don't even know where to start?
1. First off the defender covering the target for the screen shouldn't jump the play in the backfield. They shouldn't be making that assessment until the ball is passed. You already have linemen and blitzers coming off the edge to make that play, do we really need to make it even worse? I think this would alleviate a lot of the basic screen problems alone.
2. The number of attributes needed to successfully throw a screen is a bit ridiculous. Between super wobbly passes, off target passes falling down, or just being unable to make the grab. It is just plain ridiculous. I can see not being able to make a grab here and there but the pass and catch shouldn't be that hard. However that might have a lot to do with point 1 often times.
3. I don't know if this is due to the new coverage stuff but reactions to screens are instant.
http://glb2.warriorgeneral.com/game/replay/31303/3047902 Safety pretty much reads screen from the snap. Dude is 10 yards deep and reaches the screen point nearly the same time as the HB.

I have another replay in my private scrim earlier where the TE didn't go out because screen and so the LOLB must have read HB or one of the WR's because he immediately ran to the weak side of the field at the snap. Gonna watch the rest of this game and see if I can catch En Fuego doing that at all.