Davis is younger, bigger, faster, more physical, etc. I think he'll eventually be pretty decent. Smith is pretty awesome--I was hoping we'd pick him. But all told, I'm pretty happy with Butler.
Either Springs or Bodden are going to be the biggest contributors, at least if you measure it in terms of the upgrade they represent. Last years WR corps was excellent. Ditto this year with Galloway. We put our best rushing totals in two decades in 08. Taylor just adds to the depth. Cornerback, however, was our obvious weakness, and ended up killing us in several key games. Even worse was our inability to cover the middle of the field, but with Mayo and Guyton--and Chung, let's hope--I see that become less of a problem. Our secondary needed upgrading in a big way, and two established, former pro-bowl vets definitely helps. I like our youth movement, too.