The Roto 35 weights 3.6lbs with ignition and muffler, however the ZDZ 40 weighs 3.15 lbs with ignition, minus muffler, so if you add a pits style muffler you probably come to about the same thing.

After considering all the facts I think I might go with the ZDZ 40 RE and a small light Bisson inverted muffler. Not the best setup for power, but cheaper and it will hall a 13 lbs plane with authority. Not just that but the total cost would not be all that much more really! And at 13lbs this plane flys very light.

Any way I guess I just made up my own mind.