That's correct.
They both create a hidden folder on each drive, and store your files within them. This means you can take a drive out of the machine, plug it into another, and just look inside the hidden folder to access all your files.
During Drive Bender's beta testing, I had a couple of software failures, but their approach meant that the data was still intact even though drive bender itself needed to be removed and reinstalled.
Server 2012 on the other hand formats the drives in such a way that you can't do that. During that program's beta phase, I had a glitch with the software, and all data was lost. Fortunately it was just a test server.
Both Drive Bender and DrivePool support duplication like Drive Extender did, and if a drive fails you can replace it and get your files rebuilt.
Drive Bender supports multiple pools. You could for instance create a media pool on drives 1,2,3 (your fast drives), and a data backup on drives 4, and 5), and in each case, have duplication turned on so you could lose one drive from each pool and still recover all your data.
Last I checked, Stablebit Drive Pool had plans to introduce this feature, so they may have it now too.
One of the two also works on any recent windows OS - you can use it with Windows 7, you dont have to be using WHS. I cant remember which of the two it is though.
I'd go WHSv1, or WHSv2011 with drive Bender or Stablebit DrivePool, over Server 2012, for data portability. If the server itself fails, you cant move the drives in a Server2012 to another machine easily (and maybe not at all); with the other options you can, easily.