vSphere 5 Host Cache Configuration
I haven't had a chance to really test the effect of setting a "Host Cache Configuration" yet I also noticed there seems to be very little when Googling around for more info back in July. Actually, there were no relevant hits actually. But now, there is a bit of info beginning to surface, but nobody that I can find is really saying how well it actually works. Very little from VMware yet.
When I get power back to my home, will try a little more testing of this feature...
Added 8/31/2011:
A very good read on this topic found here