If you find this or any other answer useful please consider awarding points by marking the answer correct or helpful

Before starting with ESX 3.0.1, we contacted VMware and had some lengthy discussions about using RAM configuration. We went over in painful detail exactly what we do, and they recommended that unlike 2.5.x, an 800MB console would not be needed, 272 was the perfect number. We continued to swap, and crashed ESX a few times. Since moving to 800, ESX has returned to a stable condition.

We did run 512MB in some of our smaller systems with success for a few months, that worked well enough. I did not continue to persue this option because I wanted to run audits across hundreds of ESX servers, and it was easier to just check for 800, rather than build in exceptions for my audits. call me lazy, but 800MB works quite well and while swapping can occur, it is rare.