I played with the box volumes and have come up with the following. It seems that with price comes performance. And with performance/price comes volume of box for desired low Hz. I believe I understand why Steve likes the Fi over the Mach - SPL. I am still not sure what the Transfer Mag graph is telling me - efficiency???
So the question becomes how much enjoyment is there to be had by having higher output around the tuning point. I guess it is personal preference adn it can always be turned down. This is why it is all up to budget.....
*edit*-I will repost correct graphs.