Ad-Aware vs Spybot S&D

A post dedicated to my friend Tow Yuan.

Inspiration:
Tow did a scan using 'Ad-Aware Free 07' today(Wed) prior to system shutdown. When asked of his opinion on 'Spybot Search & Destroy', he expressed that Ad-Aware is able to detect and remedy a wider array of threats as compared to the former. The stage is set =)

Note that the following test is based on my perspective, and results produced are analysed based on observation. As such I urge you to use any information posted for reference only.

Test Criterion:
-Is Ad-Aware able to detect threats after a Spybot S&D scan?
*If (the above is) true- how significant is the threat(s) detected?- On a scale index of 1(Low) to 10(Critical)
-Will Ad-Aware interfere with the operation of Spybot S&D?
*If (the above is) true- to what extent is the interference?

Software Edition: Ad-Aware 2008 Free
Interface:


Process:
-Spybot S&D Scan History: Did a full scan the previous day(Tue), using the latest updated definitions
-Installed 'Ad-Aware 2008 Free', system not restarted
-Runned 'Smart Scan', scanned using default settings

Results:
87 Infections, but on further analysis:
-2 Adware.Agent threats with threat index 5(medium): A .sys file and a Registry key
-3 Most Recently Used (MRU) lists (like recent documents) with threat index 0
-82 Cookies from Firefox and Internet Explorer with threat index 3
*The main concern here is the 2 Adware.Agent Medium threats. MRU lists are fairly insignificant, and Cookies can be detected by Spybot S&D too.

*But on a side note, Ad-Aware's scanning rounded Cookies from both Internet Explorer and FireFox(by scanning 'Program Files')- Something Spybot S&D didn't do, because my default browser is Mozilla FireFox(so, is Spybot's scanning oriented to the default browser only? Possibly overlooking possible cookies from other browsers, but this only applies to non-Internet Explorer users).

Conclusion:
-Is Ad-Aware able to detect threats after a Spybot S&D scan?
Ans: Yes, on a small scale if you're using a 3-tier defence structure(Anti-Virus, Firewall, Anti-spyware 'Spybot S&D') which is similar to mine. As for threat significance, according to an index of 2 detected threats at 5(Medium)- there might be some concerns depending on the type of threat detected by different users.

-Will Ad-Aware interfere with the operation of Spybot S&D?
Ans: Possibly- from my experience, Spybot S&D displayed a notification message indicating possible interference on program startup after I installed 'Ad-Aware 2008 Free'. It's true: Strangely, I was not able to remove the Internet Cookies being detected on the first try(Error message was produced stating that I had aborted the 'Scan'- somehow unrelated?), but that worked out after rescanning.

This is what I observe as for now, will update this post if new dicoveries are made