I got a chance to try one out last weekend. Took some shots in the back yard with my girls--nice focal length for that--sometimes the 77 is too long (small yards in the big city).
Now my kids aren't as well behaved or as clean as Frank's, but thought I'd share anyway. My backyard is also kind of a mess...
I find it very sharp, love the bokeh, and the AF is rock solid. I did some shots at 1.4 just for the effect and the shots have a nice dreamy look to them. The chain link fence has never looked so good!
Weather sealing was a must once they got out the hose...
f/2.8:
f/2.5:
f/1.4:
f/2.5:
f/2.5: