I have posted this before, but I do not agree or think doing board specific question banks with your systems is beneficial for a few reasons:
1. Most of the board questions you are going to get are going to be more superficial than the types of questions you should be getting in your actual class. For example, on boards they may as you what the most common gene mutation is for a certain disease...but in class they can ask you the 2nd-4th common mutation. This is just an example, but you get my point. If you are taking a class (repro, for example), you should be CRUSHING any board type of question. It's a lot different when 5-6 months down the road you are asked board questions on repro and you are trying to remember things. This is why I think you should be using another resource to LEARN the material (PreTest, Robbins questions, online questions other than boards question banks) because it will force you to learn the material more in depth.
2. If you are using a Q-bank, RX for example, in December and you come across a really good factoid, what are the chances you are going to remember that in June-July when you take boards? Not very. I think the best way to use your boards banks is to start with Kaplan, then RX, then UW. Start Kaplan 5 months out from your exam when you start reviewing for boards. That way everything is much more "fresh" in your mind.
This is just my opinion on this and I know many people believe in doing questions with classes...so you just gotta choose which works best for you.