It's hard to look past NIS for its strong performance, ease-of-use and negligible impact on the system. It's a very streamlined product, with cohesive features that are so seamlessly integrated and efficient, it is a de-facto benchmark for all-in-one suites. The positive experience starts with installation - NIS installs in less than 2 minutes, compared to the lengthy and cumbersome installation of most of their competitors. Silent and unobtrusive, strong and light protection, there's not much not to like.
The few issues that counted against EAM 5.1, such as heavier impact on system performance, very slow scans and an above average FP count, to name a few, have been convincingly addressed with their 6.0 release. What has never been questioned is the excellent protection. Combined with an excellent firewall/HIPS [OA, Comodo, Privatefirewall], this is a formidable combo.
I'd have to go with EAM 6.0 & Comodo Firewall.