I had an Aeromaster some years ago and flew it for four years with a Supertigre 61 in it. I am now flying an Astro Hog Bipe with a Saito 80 in it. They both fly wonderfully, but my vote goes to the Hog Bipe if only because it is an easier build. Flying qualities are about the same IMHO. I think that a lot of flyers will agree with me because Sig is still making kits but GP is not. Although Aeromasters command some hefty prices on Ebay, I think the Hog Bipe is a better buy if you are going to build and fly. If you are a collector, then that is another story altogether