Warren,
I too recently bought a Super Clown.  I only got in a few flights before the winter set it, but I was averaging 2700mAh for 6 min flights.  I was doing more maneuvers than the pattern, so the 2700mAh number may be a little on the high side, but I doubt you could get away with a smaller battery.
Rick

Hi Warren
I did the the development on the current edition of Brodak's E-Super Clown so I think I can help you with your question.

Basically the E-Clown is set-up to fly Sport-Stunt speeds and fly for 6 minutes without toasting anything.  The 3Sx3300 pack is up to the task, and it weighs 8.75 oz - total RTF weight of the SC is usually around 30 oz.  To fly with a lighter pack you will have to reduce the flight duration and/or flight speed.

There are a few things to watch for:
* The motor has kv=1500.  That means it is suitable for 3S (11.1V) packs.  
* The SC is designed to pocket the battery inside the outboard wing - that is secure, achieves the correct CG and easily changed out.  It also provides the correct tip weight!  The battery pocket is 20mm tall by 50mm wide.  Thus you need to find packs that fit that pocket.
* The Brodak pack is supplied by Arrowind.  I have seen other brands of packs with suitable dimensions, and capacities between 3000 & 3300.  They are all pretty close to the same weight as the Brodak Arrowind - not a lot of weight savings (or penalty) available.

The only weigh (pun intended) I see that you can save substantial weight is to use a much smaller pack and forego flight duration.  You might be able to use a 3Sx2650 if you shorten the flight time to around 4:30.