Anna, I think the Quest Study Bible gets underrated among Reformed folk simply because it looks simple (and therefore must not be "deep" enough). In fact, the content makes an easy-to-read guide that's a great help to people who are not very familiar with the Bible but want to read through it. If you find it helpful, by all means use it. The material is solid.
I think the question-and-answer format is one of its unique strengths. When I'm preparing to teach a passage of Scripture, I will sometimes look at the Quest Study Bible just to prepare myself for the type of questions I might get from my students. Often, I find myself appreciating the answers as well. They tend to be direct, brief, informative, fair to opposing views, and yet theologically conservative.