Really different bikes. If you are into the whole "cruiser" scene, Thunderbird it should be. Otherwise the Green Bullet 500 looks really nice as a retro machine. And with a carburetor you have one less hassle on your head. RE has good and long experience with the carburetor and you can tweak the carb as per your riding conditions. Having said that, RE has pretty much handled the initial niggles of the EFI on Indian bikes. But still they are not giving us an O2 sensor - so that's still a negative for me. I'd pick the Green Bullet 500 personally or if going for EFI - the Desert Storm. Cheers.