I didn't do them. From what I hear they are too easy. Of course, there's going to be a million posts after this one telling you that like 80 of those questions repeated on the real test. I mean, if they are going to repeat an easy question on the test, you're probably going to get it right regardless. If your exam is a couple days away, I would just skip out on them. If you got a couple weeks and time for them, check them out.
If you have some time to burn, I'd go with the released questions. It'll give you a chance to see the format of the test, get familiar with the tutorial, and perhaps provide a bit of a confidence boost (I thought the released items were fairly easy)
Well, I did have a few of them on my test... But anyway, I got through all of the questions and answers in a lot less than 5 hours. They are easy, yes, so it won't take the full hour for 50 and you can skim a lot of the explanations and only read the ones you got wrong. But if you are on the last day, I agree with the above, skip 'em.