all my specs are in post #3 above... the actual model of the system is an HP x4000 Workstation.

Since my last post, however, I think I've narrowed down the probable cause of the slowness. I disabled QoS on the external interface and the speeds are all where they're supposed to be... 8Mbit down / 768kbit up, or just under. If I enable QoS with ANY settings, the total speed drops back down. On the WRT with custom firmware, you can disable the inbound QoS. I don't see any way to do this within Astaro. Any ideas on this?

EDIT: I also noticed something else interesting with QoS disabled... I'm currently downloading two very large torrents (Ubuntu and Kubuntu DVD's) with several hundred peers connected. It's downloading at a solid 8Mbit rate without problems. But I noticed even after 3.5GBytes of data, there's been NO errors or dropped packets on the external interface. I was seeing around 400-500 dropped packets when QoS was enabled. Is QoS broken? I'd be curious to know which QoS method Astaro uses. It feels like the old WonderShaper.