There is no real gain for racing a hex. People always say they're faster because they've two extra motors but remember that they also have more surface area for drag and are much heavier with a much bigger battery. That extra weight will always tax them in the agility department and the ability to come out of a crash un-broken. As far as acceleration and top speed, that comes down to the thrust to weight ratio and the prop pitch and rpm versus the frames drag. Comparing the same setups the quad will always win. People fly hex's because they look cool.
Hex's with angled motor sayings are because of the TBS Gemini which is a real over priced gimmick. Angled motors reduce the frame tilt by the angle of the motor tilt which is usually about 5 degrees but a high powered quad will usually sit at 40 plus degrees when going so 5 degrees won't make a scrap of difference and if the gemini had the power to do that (which it doesn't) you would find its "aerodynamic body" would be worthless at that angle.