I've recommended it to all my family and set it up on several clients comp's for use. It's got a very small foot print (even more so if you turn off live scan and use it for periodic sweeps), so it's great for the p4 relics that people love to hang onto. No firewall is a down side, but you can't really complain being that it's free. My buddy uses it for his main comp for data recovery, and it's blocked conficker and several other nasty worms.

Onestop is the best recovery for windows, but MSE is great for a (free) desktop AV solution.