Um...didn't this end in Gotenks getting spanked in the movie? With that being said Bills lolstomps. He took down Ultimate Gohan like he was nothing and Gohan is stronger than Gotenks.
@Dream: In case you misinterpreted the reason why I stated the solar flare is either lightspeed or really hypersonic is because I'm not too sold that it is lightspeed. It's just you gotta admit a very fast attack. Also I've noticed you seem hung up on Goku only being able to move at Mach 120 with Kaio-Ken. While this would reasonably be the case for long distance travel acting like this would be the fastest he could go in a short burst is wrong. When Goku flew across Snake Way it took about a day or so. That means he was moving at that constant speed for that long. Why do I bring this up? Because the cast of Dragonball do not have infinite stamina(Except Buu and the Androids I suppose) so he would have to pick a speed that he can maintain for a while. Otherwise he would just burn out quickly before he got to the end. Remember the fight between Vegeta and Android 18? When Vegeta was fighting at a speed too fast for him to maintain he burned out and got beaten by her. When you're running a long distance you don't just sprint as hard as you can do you?