I am having problems with even heat in my oven.  The loaves baked on the top rack pop up just fine, but the loaves on the lower rack tend to spread out a bit rather than springing upward.  The difference is easily noticeable.  I use stones, but I'm thinking that's not enough.  I've been looking at the HearthKit, and Fibrament stones, and also at someone's homemade HearthKit (tiles lining the oven walls in addition to baking stones).  I've also thought about convection, but to get even heat, I'm thinking I'd have to turn on the convection at the beginning of