In short, I seem to have a knack for finding hard to debug issues.
1) I have an issue related to some parsers I'm working on re: large # of stack pages in use. Eliot provided some helpful tips a couple of months ago that really helped here. It turns out I had two different issues related to this, one resolved (thanks to the image side VM params he pointed me to) the other still outstanding (probably a deeper structural issue and I'm thinking that the easier way to debug it will be to dial back the stack pages and let it crash earlier). These are bugs in my code and not not the VM.
2) Under heavy load I'm having problems with Event Tickler spiking in CPU usage (50% or more) and the image becoming generally unresponsive. Event Tickler never seems to recover once in this state.
3) A variety of site-specific network socket issues. I think I've done about all I can in the image and need to start looking in the plugin but i suspect that's only going to be productive on live connections w/ gdb.