Atmosphere is really cool, and of course, the fact that it is still "new" is what is keeping it so hard to get an ADR. I suspect it will become easier over time, and it's definitely worth it to eat there at least once. We have done dinner, but not lunch, although I consistently see people saying that lunch is better than dinner...which I suppose probably supports expectations. Nobody goes to BOG expecting an outstanding lunch, so if expectations are low, a meal that turns out good will seem even better! I think we all had very high expectations for dinner (maybe the fact that they serve beer and wine makes it seem a little fancier?!). To be fair, it was good and actually priced decently compared to alternatives. It's definitely the nicest food in the Magic Kingdom and probably the best (nice and best do not always equate). But as most folks would agree, that's a pretty low hurdle, at least if you're looking for "fine dining" in that park without having to go to a monorail resort (which we tend to do as often as not).
If you are planning to be in MK one night for dinner, it would be worth some continued effort to try to get the BOG ADR (they tend to open up as people cancel randomly, so there's a reasonable chance you could end up getting one). But if you don't get it, I would not be too concerned.