There is a review here:
http://www.esecurityplanet.com/windows-security/review-microsoft-system-center-2012-endpoint-protection.html
The key with SCEP is it only provides antivirus protection. No firewall, no IPS, no zero-day type scanning or no other features for that matter.
As someone who was asked to review it and compare in the past, my opinion to is to stay away from it at all costs. The risk to your business goes up significantly with it in place.
SCEP is free with SCCM so every company is taking a hard look at it.