SpywareBlaster sets "killbits" in the registry for ACTIVEX which are known to be malicious. Doesn't have to run. Once it does the job, it's done till the next update.
Spybot is different technology and purpose. Spybot's immunization adds a list of known bad URLs to the list of restricted sites in the IE. So it doesn't have to run either once the list updates. Spybot does other things as well, but I don't know the details, I think it runs as BrowserHelper object in IE.
Spybot's TeaTimer does run all the time watching over the web activities, registry changes etc.
I'm going to confuse the whole issue some more, but hopefully after reading this, everyone will have a better understanding of how the various protection tools in SSD work and how they may differ, or not, from the protection SpywareBlaster offers.
First, it's important to distinguish between Immunize tools and TeaTimer (which is a watch dog, a resident guard). The immunize tools are passive. Once applied, they will do their job, whether Spybot (or SpywareBlaster) runs or not. They use some of Windows native tools and resources to create blocklists. SpywareBlaster has a variety of protection modes, but the most important (and better known) one, is the ActiveX killbit portion of it. After all, that's mostly why it was written. What that does is it adds a pointer in the registry for a specific baddie (identified by a CLSID or Class Identifier - in other words, a unique ID to the particular piece of code) and sets Windows to deny it access to the machine. Stops it in its tracks before it had a chance to take hold. Spybot, has an equivalent (meaning, it does the same thing, in the exact same way) in the Immunize feature. In earlier versions of Spybot, the Immunize feature was just killbits, every other passive protection or tool was in a different area with its own name, now they are all bunched up, which leads to the confusion you see in this thread.
SpywareBlaster also offers a "Restricted Zones" for IE blocklist. Spybot has one of those also. This adds known malicious websites to the Internet Explorer restricted zone, which disables pretty much all access from those websites to the machine (but only for IE! - FF or Opera, or any other browser not using the IE engine, is unaffected by those settings).
SpywareBlaster also has a cookie blocklist. This works in much the same way as the Restricted Zones list, but instead of focusing on websites' access, it prevents any of those domains from dropping cookies on the machine - highly recommended, and very useful to keep ad cookies at bay. Spybot also has this. As you can see, there is substantial overlap in the features. Where they differ, is in the maintenance of the blocklists. AFAIK, the blocklist for SpywareBlaster was usually the leaner one, and the most current. I have not compared them lately, though. Even if there is overlap, that does not mean conflict between the two, as they both use the same Windows resource (namely the registry and the IE security settings).
The SDHelper.dll (Browser Helper Object) in Spybot's resident protection is something else entirely and only acts in trying to intercept 'bad' actions from an open web site. It filters traffic and queries between the browser and the server to snoop on what's going on. This in theory is good, but in practice, it's somewhat ineffective and the benefits are minimal to using it. SpywareBlaster does not have such a feature, it is strictly a passive protection tool. The Spybot BHO is an active one.
There are other tools included in both programs, such as the hosts file in Spybot, the locks you can use in SpywareBlaster and the snapshots feature.
TeaTimer is another active tool, but it is mostly misunderstood and overrated (for most folks). If you cannot tell what the prompts mean, by all means, don't use it. You're only hurting your security, not improving it. If however, you know what the prompts mean, then yes, it CAN be an extremely useful and efficient tool, but it has to be maintained! It will alert you to specific registry changes or attempts to change the registry in certain key areas, such as Run Keys, and other system critical registry settings. A neophyte to the registry should NOT be using this tool. Its effectiveness depends highly on the level of knowledge of the user behind the controls. If you get annoyed everytime a prompt appears asking you for what you want to do, then please, don't use it. And stay away from the "remember this decision" (or its equivalent, I forget how its labeled now) button!!!
Spybot used to be renowned for its effectiveness at dealing with current malware. The Immunize and other protection tools were added later on and were only a 'bonus'. What Spybot is, still today, is a very powerful and versatile toolkit. Its detection rates and removal capabilities have dwindled with time and it certainly hasn't been keeping up with some of the other anti malware programs out there as well as it used to. I can't compare SUPER AntiSpyware to it, because I have not used SAS personally. MBAM (or MalwareBytes Anti-Malware) is a great removal tool though its protection capabilities are limited, unless you buy the full version. The newer version of it, includes an IP Blocklist (paid version only) that acts much like a firewall, but without user control. It uses a blocklist and denies access to any IP recognized as bad. This (I assume, I have not tested myself) only works if the resident portion is running.
As for SpywareTerminator, I can't say I know what they are up to now, but they used to have a shady reputation. Prior to entering the anti spyware market, they were adware distributors. I, for one, would not put my security in the hands of ex-adware distributors. Principle. Of course, I'm not saying they are bad, or rogue, but they used to be, and for me that is enough. There's plenty of other apps that do similar (and probably better) out there that don't have that ex-con tag. So strictly out of the two, Spybot or Spyware Terminator, I'd stick with Spybot, hands down, if only for its track record as a free community app.