How do they impair productivity or battery life? If you don't like them you don't have to use them so they can't possibly impair your productivity, and even if you do use them what are they doing that will impair battery life?
I agree about missing Expose though.
They impair productivity by replacing Expose. With Expose, I was able to think "Hey, the safari window I'm looking at right now isn't the one I want to be looking at," hit the appropriate expose button (or click and hold on the Safari icon, another feature removed from Lion) and then click the correct safari window.
With Mission Control, after thinking that, I hit the mission control button, then I have to look around to find where my safari windows gathered, and then they're all obscuring each other so it takes longer to find the correct one, and eventually I get the right one. I estimate I waste several seconds with Mission Control each time that I wouldn't waste if Expose was still around.
As for battery life, I'm not certain about this, but I'm fairly certain that opening Xcode or iWork documents on my original Mac Book Air is a relatively demanding task. With Resume, when I launch Xcode, all three of the projects I had open previously open at once, only for me to have to close two of them because I really only wanted the one. So I waste time at least (I'd say projects average on taking 15 seconds to open), if not battery life.
I do like the graphical style of several of the applications... although I just remembered, Front Row, for no apparent reason, is uninstalled when you upgrade to Lion. Probably one of my top ten most used applications on my iMac (which I have instead of a TV,) and they simply removed it. Now I have to use DVD Player, which isn't as Apple Remote friendly. Doesn't really hamper performance or anything, just an annoyance of Lion.