brumellTend to agree with your opinion re pit vs underground, Bob, but also seems way early to state anything with certainty. The other problem is I am at a real disadvantage as I can not access the John Royall presentation. Tried off and on all day by going thru the pfn site you suggested and also the short cut to page 7 suggested by hatter. Neither one will finish loading for me. Will keep trying.
I will say this about pfn, the info they have provided thru their site has been real good and real plentiful. Sounds like the John Royall presentation is also. Compliments to them!