Do you have any A/V running? Any real-time scanning would skew IOmeter results by huge amounts (i know, I accidently did it once!).
Very interested in how your implementaton has progresed. We are running a near identical config and are experiencing huge performance issues with Citrix. We are having to add additional Citrix VM's, now about 8, to handle a farm of 250 users. This is not what I expected. We have reduced the processors for each VM to 1 as reccommended but performance is deplorable. Any specific settings for the VM or host that would make a difference?