With the materials in the kit, I think it will be nearly impossible to build one under 9.5 - 10 oz. I tried to go light with my build, using a 2-cell battery and a higher kv motor. I still ended up at 11oz RTF. I can only see me being able to trim maybe an ounce from that...It still flies nice though.

A friend of mine (who is now building a Reflection after seeing mine fly) and I were talking about tracing all the parts and building a couple from depron using traditional foamy construction techniques. I think we could get them pretty light that way. Of course, they may end up being indoor or calm day only models then.