Can anyone tell me what the differences are between zero clearance and masonry fireplace doors? I am looking for replacement doors for our Majestic zero clearance fireplace, but every dealer I've talked with has been very vague on why the doors are not interchangeable between the fireplace types. It seems like the zero clearance doors are much more expensive, so unless there is a good reason, I'd like to consider masonry doors as well.

Any help anyone can provide would be greatly appreciated!