I finally did this last year with Gary E and some other folks last year, and I gotta say that I don't really recommend it. Lots of flatwater for about 300 yards of marginal mank -Gary screwed up his shoulder on one drop. Now, I know how you love your mank; but with everything else coming up, I wouldn't make that drive.
Check out some photos on Alex's website: www.merelyafleshwound.com
Go to Paddling>Stills>Main Menu>Arkansas> Grape and check it out.
I think the consensus on our trip was that we wouldn't go back there Unless it was above 300 and nothing else was running. It's got 7 cfs in it now...