I have twine bvm rafale and changing my skymaster mig 29 to twine ,two vt-80s and my next project will be the big 120" long F-18 with two turbines setup ,the biggest advantage is the fast respound and grate power no power losing on the y pipe and the sound it's much dipper and powerful when using two turbines ,twine is way to go the two smaller turbines have much faster respond than one big.