I tried to preach this years ago but it did no good. Once I realised I was dealing with a crowd who believes everything they are told and has no real track experience, I pretty much gave it up.
It was entertaining though. Back then, they were trying to say stock LS1 heads were flowing 300 cfm without porting. That was already after I had seen the flowbench data on a pair of ported paper thin LS6 heads that barely flowed 350 cfm @ .700.
What aggravates me is, there is a lot of really experienced people on this site that know all these claims coming from the LS crowd are complete bs. I guess they won't refute any of the bs because they are afraid of losing potential customers.
The L92 head, from what little research I've done is definitely better. It is the only head ever casted by GM for a small block that is a good 'bolt on' performance head. Is it better than some of the old stock Ford stuff? Hard to say. But if it is, it isn't enough to justify the cost and hastle of swapping an LS motor in just to be able to use them. They may be a little over $1000 for a pair, but for the same price, you can buy an eqivalent head for a sbf. Keep in mind these guys are still paying upwards of $2000 for a used motor. For around $1000, the average person can build a stock short block sbf, install the equivalent heads, intake, carb, cam kit, and have the same performance for the same price without the hastle of a hybrid motor swap.
The good thing about sbfs are the stroker kits are really cheap. When you get ready to add more ci, you definitely have the cost advantage over the LS motors.