Please see my review on the 764D and the lie-flat bed seats from back in July of 2009.
http://www.flyertalk.com/forum/delta...eats-more.html
To each his own when it comes to personal comfort, likes and dislikes. But remember this, its a significant improvement over what they're replacing and, they are J seats, not F. I found the 764D BE seat to be very comfortable with only some difficulty with the tray table. I'm 5' 11' 205 lbs and medium build. Once DL starts rolling out the mods to the 767's, I'll gladly fly DL TATL any day of the week.
As far as cramming in more seats then other airlines in J, well doesn't that all depend on how far back the J cabin extends? So, when making a comparison that airline X has less seats then DL in there J cabin, one has to compare more details then seat count.
As for choosing the WBC seat over the 76D seat, thats insanity! I mean, the flight I just took on a A332 had me playing with the seat controls until I found just the right angle so I wouldnt be sliding down in my seat. As for that, I think I'd rather try for an empty middle row in coach then a WBC seat.