I believe most of the latest review give the pay products the edge in detection and prevention of spyware. I'm particularly impressed by Webroots product at he moment, and I've seen it for a very good price recently. Being financially disadvantaged, I stick with the free products, and yes, I do recommend MS AntiSpyware.
As usual Mastertech, you seem to have a problem with simply letting people make their own minds up.
As to rootkits, perhaps the reason we don't here about any is that they are so effective that AV's can't detect them. We see plenty of the FU type pseudo rootkits, believe me. I've tried BlackLight on some infected computers, and have found some hidden malware.
MS itself is taking the problem seriously enough to add rootkit detection to its Malware Detection Tool and AntiSpyware.