2 questions: Silpat and the yummy factor

I am about to begin baking for my second annual gingerbread assembly party, where a bunch of us novice gingerbread house builders half-build and half-eat our way to fun gingerbread creations. I do the baking myself before-hand. Last year, I used Silpat instead of aluminum foil to bake my gingerbread pieces. Is there any advantage to using foil over Silpat? I figured I would ask the professionals.

Also, last year, I used Martha Stewart's gingerbread recipe, which was sticky, and when it rose, it changed the shape of my pieces a little. Given your mention of baking soda for cookies, I am guessing that gingerbread is yummier if it rises, but is also not as flat for construction pieces. I am thinking of making the house pieces of gingerbread from the non-baking soda recipe and the 3-D gingerbread trees/ people from the baking-soda-added, yummier recipe, since those are the pieces that are usually eaten first, anyway. Question is: for simple houses, what both tastes best and is best for building? Can you have it both ways, or does taste sacrifice building quality?

-Caroline

P.S. Thank you for all of the great ideas on this site! Browsing through all of the pictures is really useful and fun.