I already did mention some issues. Now I found some more.
Even if you have it disabled in the options. MS-AntiSpyware still places itself resident as soon as you start it. If you close it, it still stays resident.
Also removing it is a lot of work. Not only doesn't it remove all files, it also leaves 34(!) unneeded registry keys behind which you need to remove manually or with a decent registry cleaner.
My honest opinion about this beta version:
It still needs tons of work before it is something we really can use in a decent way.
The question also remains..... Will the final version still be free?
At the moment I would say: Stay with Ad-Aware, Spybot S&D and HijackThis and drop the MS one.