Yes I have reviewed all of the monitors mentioned, however I cannot give you my recommendation in a public forum. I work for Cornerstone and I'm biased, so no matter what I recommend someone would jump all over me.
What I have done is put together a monitor selector on my web site that may help you make a decision. Look HERE for my product selector tool, you can compare these units and since I designed it, the score each unit gets based on your input would most likely be the one I would recommend.
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com
johnNASA, I'd get my monitors from http://www.techonweb.com They're rated to be very good in service, product pricing, etc. I priced it out, and with $41 shipping, ONE G420S costs $500 flat! Not too bad considering Sony wants $530 without shipping, but then again, you're buying directly from Sony.