Ok, so I've only been playing with Mindy for about 24 hours, but this build is looking a bit more promising. Right now, I'm copying files to my file server, listening to music off my Roku (also from the same VM) and importing CD audio on a second and nothing seems to be bogging down like before.
I still don't seem to get the write performance that I would want from the network. It still seems to be writing in spurts (20-30 Mb straight and then a pause), but I think these can be fixed via filesystem fine tuning.
Once I have a good, working system, I'll post my complete settings.