Yea, F seats look pretty decent (though nothing compared to 180 lie-flat ones). Based on the airliners.net photo database, 333's F seats are just as wide as J seats but with more leg room and supposedly more recline. I can't comment on the service, however.

Since I am on DL 30K mile award, one of the best deals around, I won't complain, but I surely will try to see if I can be assigned to those F seats (since KE doesn't sell F out of BKK) - I know they are usually for KE elites or full fare J pax but it doesn't hurt to try. I tried on MNL-ICN on KE 744 but that flight actually was selling F, but didn't sell a single seat.

Speaking of best mileage redemption deals, here are some of the list based on my experience:

DL 30K award for J with KE (N.Asia to S.Asia)
US 30K award for C with *A carriers (S. Asia to Central Asia, ex. BKK-MLE)
US 60K award for C with *A carriers (N.Asia to South Pacific, ex. ICN-PPT)
US 60K award for C with *A carriers (N. Asia to Central ASia, ex. ICN-MLE)
UA 90K award for F with *A carriers (Central Asia to South Pacific, about 10-15K less for NZ, ex. MLE-PPT)