Personally, I favor slightly behind. The Axiom FAQ says "Ideally, surround speakers should be either wall-mounted or stand-mounted to either side of the couch or primary listening area, from one to six feet higher than seated listeners' ears, and slightly forward or rearward of the listening area if you wish." Sorta leaves it up to you, doesn't it?

Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton