Its hard to say because snakes do not give as much feedback as other animals may. You just have to go by the basics. Will my snake eat regularly? Is my snake excreting wastes normally? Does my snake shed perfect? Is my snake constantly roaming? These are all questions you should be asking yourself when trying to figure out whether a BP and its enclosure are working.
Having experienced both glass and rack set ups I can tell you that I think my snakes are doing much better since being in a rack set up. Not to mention how much easier it is to maintain a clean environment for them.