Best Corporate Antivirus

Hi, our corp license for McAfee Managed Services is about to expire, and I’m looking for alternatives. Here is the criteria my boss has given me:

excellent anti-virus and anti-spyware detection and removal
seamless automatic virus definition update
web-based monitoring and administration

Considering Sophos, F-Prot, Kapersky products, but all three fall short in one way or another. Don’t trust Norton / Symantec because I’ve seen it cause too many issues with Windows PCs.

Does anyone have any recommendations?

Thanks!