Fastguy, first I have not done a Super Sportster twin so this is only my speculation but I have done a lot of twin and more bashes. In some I have choosen to extend the tips and some have went without adding area. All were successful from just adaquate to superb and in every case the ones without the extended wings were the just adaquate variety.

What has worked well for me on the extensions is just to add a bay to the wingtips. Easy to do and pretty quick yet without strength issues.

Your project should be a good flyer either way but I think you would be happier yet with a few extra squares at each wingtip. Its a cool subject.

John[8D]