When I took my very first ARE, I thought I should take an exam that matches my work experience. That part of my thinking was good.
The bad part was that I assumed I knew how to study. After all, I was a pretty good student in school. Sadly for me at the time, ARE turned out to be a rather different experience. When you are studying for a school exam, you know exactly what book to read (usually it's one or two books). You will likely have written notes from your class that's taught by an educated professor... You know with certainty what content is going to be on your exam. Questions will directly refer to the chapters you read.
That is definitely not the case with ARE. Suddenly you are all on your own, there's no one to hold your hand, and yet you have a huge pile of nebulous stuff to figure out. And guess what - the studying content is all open ended.
Except for study materials being much more open, the way that questions are constructed for the AREs is very different from a school exam. We all had that one professor who looked for those teeny tiny hidden facts in order to give you an A. ARE is not particularly interested in those tiny facts. What ARE will test you on is THE APPLICATION of larger concepts. You need to know those concepts REALLY well in order to pass an ARE exam. A school exam is going to test you on definitions, big facts, small facts, some critical thinking, etc. An ARE exam will, on the other hand, take a handful of larger concepts and put you through a variety of scenarios in which you have to give your judgement of a given situation. In order to give the correct judgement in all those situations, you need to know large concepts inside out. For example, for my first CE exam I only brushed through bidding, thinking Oh bidding, so straight forward, just use common sense. What a rookie mistake haha!
Another difference between the ARE and any school exam is cramming. I am guilty of cramming for school exams, and then forgetting half of the items three weeks after. Because when you're in school, there's a lot of subjects on your plate, and it's difficult to be on top of them all at any given time. That's why we hit books in the last hour prior to an exam. That's not the case with the ARE. For the ARE, however, it's you who determines all schedules and balances the amount of stress and busyness. You can study as long or as short as you feel appropriate. However, one should NEVER cram for the ARE. Firstly, because that's a recipe for a fail. You can't just cram all the scenarios. I would much rather pay rescheduling fee than cram for these tests. Secondly, this is a professional licensing exam. You don't want to forget half of the content in three weeks time.