Hmm. At first glance the more solid stands didn't improve things, although I may just have lost some artificial bass reinforcement from the tote bottom resonating. Coupling to the floor seems a bit better, ie the bass can be "felt" more readily, but there still seems to be a loss of very deep bass relative to having the speakers on the floor.
I guess next steps are (a) moving the speakers closer to the front wall to see if that helps to make up for moving the woofers/ports away from the floor, (b) raising them a smaller amount, trading off better midrange/imaging for better deep bass, (c) beanbags or sitting on the floor.
Option (d) - taller speakers -- looks a bit better every day
