I bought a single fan unit.  It seems to work very well.  It is much lighter and a bit smaller than my s3's.  I have it on its side so the heat sinks are pulled by gravity toward the chips.  It is a little like a rocket, so that must be one powerful fan.  Denser heat sink fins than older s7's.  Loud, but don't know how it compares to other s7's.  Stable at 700 MHz, and I think it's a little faster (GHs/s) than older s7's but I'm not sure.  I'm a little worried about a single point failure on that single fan.

Does anyone know if s7's can support mining two pools at once?