Okay, so it's been a while since I posted this, glad to see everyone's opinions. I've started using ESXi a bit more, to see what it's got to offer.
The HA/DRS point is a good one, and that's my next point to experiment with as right now, I tend to just use OpenBSD with it's 'carp' feature offering HA, but if there it a better way to do this, them i'm certainly interested
Does anyone know of any software that allows multiple ESXi machines to be connected too at the same time, instead of needing the application open a different time for each physical server?!