I would agree with horndog, though the final paragraph has pros & cons: con would be that you feel like you missed something in the training & start to wonder if you missed seeing where else you were to go for additional materials. It's a bit disconcerting. I was told by TestOut that they used to do it in their old CDs (which is what I have), and he gave their reasons why they used to do it, which did make sense. Either way, supposedly now they've changed, but I can't afford to buy a new set, and they've helped me through several tests.
One thing horndog didn't mention that I like is that the sims are actual simulations. That means I can try all kinds of things, then click the reset button & do what they want (so as to be scored as doing correctly). They aren't complete - say in DNS, it won't let me right click on the top link (DNS itself) to practice those things - like adding another DNS server to the console. Also, sometimes from the scenario they give I want to do an IPConfig, and in most of the sims it won't let me.
But so many products are not real sims: you can only do the steps they want, in their order. In TestOut, I can try 2 or 3 or 4 ways to do the same thing (though it won't always recognize that it was done correctly if you use some alternatives). Overall, I like TestOut.
I have done most of their MCSE 2003 courses, and they focus on the subject matter of the tests and do a very good job of explaining it.
This is what they offer:
A lecture on a particular subject, then a walk-through, then they have a hands-on simulation and you are actually graded on the simulation if you accomplished the simulation. At the end of the subject, they have a short exam on it.
What I do not like about it, is sometimes the end tests of the subject or the simulations have you do something that was not covered in the lecture, simulations etc.