We're running vSphere 4.0 on Dell PE2950 and it runs really good without any issues and just make sure you have updated your firmware, BIOS, HBAs, NIC drivers to the latest and stress test it 48 hours. You can use memory testing tool to stress test your RAM to see any leakages otherwise during production, you realize you have issues that would be bad.
If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!
Regards,
Stefan Nguyen
VMware vExpert 2009
iGeek Systems Inc.
VMware, Citrix, Microsoft Consultant