After 2.5 days running with Volt-tuned 500 Mhz, this is what currently is possible: 3.500 Th/s
That's nice

I'm a little lower as I can't dial everthing up to 500 just yet, but I have picked up about 100Gh/s over the last 8-10 hours with today's firmware release.
Firmware 1.0 is 2% better and much more stable (no jumping 5seconds rate anymore). But still the browser-pages cause errors visible in cgminer (just don't use the browser for best results).