There is not one answer for everyone; it all depends on your circumstances and on the intensity of your recent training. If you have been working your job all week with very little time for the GMAT then you definitely want to get your form back before Monday. On the other hand if you have taken two practice tests and done 100 official questions this week then you will need lots of rest so you will not be "jaded" on test day.
Winding down is a good idea, you do need lots of rest to be fresh on test day, especially if you are scheduled for a morning exam. However, depending on how you feel about your preparation you can use the remaining time to address any weaknesses and, perhaps even more important, to do a "walk-through" of the test.
I think that the best use of two days before the test is generally not in running through dozens more practice problems, but in planning your strategy for the test. Do not go in blindly hoping that you understand each and every question and that you finish each section with time to spare. Instead, focus on answers to the following four questions:
1. How are you going to prevent "silly" errors such as misreading and calculation errors? Everyone misses questions on test day, but you can minimize the number of questions that you miss for preventable reasons. For many students more than 50% of questions missed are based on preventable errors.
2. What are your time checkpoints for verbal and quantitative and what are you going to do if you find that you are running behind? At Veritas we talk about the difference between proactively managing your time versus desperation guessing on the last several questions. It is generally better to guess occasionally than to rush on every problem.
3. How are you going to handle all of the extraneous details? Be sure that you are ready for everything that goes along with taking the test, the location and parking, the checking in procedure, the breaks, snacks, the potential disturbances in the test room, (are you going to use the ear plugs?). There are things that you cannot control, such as the number of coordinate geometry questions and the subject of the reading comp. passages, but it is not too late for you to be professional about the details.
4. How are you going to get questions right? Too often students focus on trying to avoid missing questions. You can potentially still get a 99th percentile score if you miss 15 questions. Everyone misses questions. Be like an athlete and "walkthrough" the race. I recommended choosing just a few problems from each of the 5 question types and slowly walking through each problem, no concern for time, just for technique.
Answering these questions will allow you to recover from intense practice, and allow you to concentrate on performing to the best of your abilities on test day.
P.S. Nitya V You are correct, there are no answer explanations included with the official GMATPrep practice test.
