WOW...before the new FW I had one machine running at about 1.3TH/s and one running at about 1.5TH/s (at the pool).
After the new FW upgrade, both systems are running at about 1.6TH/s

edit - the "status" page in the web interface still reports about the same speed as before....1.61TH/s each...so it looks like they've been able to close the gap between what the machines were reporting and what the pools were accepting. While still nowhere near 2TH/s...but it's good progress, I've gained a total of 400GH/s with the new FW (about 0.06 BTC per day at current diff).
2nd edit - the processors are also running much hotter now. In both boxes, I've got a core hitting over 90C...a little disconcerting considering the weather here is still pretty cold and the summer is on the way. I'm going to see what adjusting the power stepping will do.