I'll give a review of the paper tests. I have not comment about the other part.
I think the paper tests are a very good resource. The key is that they are real questions from old tests, so you know when you practice them you are gaining knowledge about the real thing.
There are a few problems with them though. First, obviously, is that they are not adaptive and not on a compute, so they will not help you with exam condition preperations. You must still use GMATprep for that. The second issue is that the questions in each section range from easy to difficult.
So, for example, if you are doing a PS section, only the last few questions in each section will be very difficult. Again, this does not help you prepare for the CAT because to me, one of the difficulties of the CAT is that you don't know ahead of time if you are dealing with a hard or easy question, so you don't know if you should watch out for tricks. On a paper test, if you get a question early in a section that looks extremely easy, it probably is easy; if you get a question late in a section that looks too easy, they are probably trying to trick you. On the CAT, you don't have his luxury.
But all-in-all, I believe the paper tests are a great practice resource and I highly recommend them. I certainly prefer them to non-official resources.