Not really that much better. Safer doesn't really matter if you're already unsafe. Let's see... 6kp, 9p 4pp, 3k. Yeah, not all that relevant. At least Busa has his Izuna counters as well.
Saying everything he has would imply that a lot he had was better, busa has better counters and a better throw game, range is the same and they are both so grossly unsafe that it's irrelevant who is more unsafe (though Busa has 3F+K which is a tracking guard break which gives him advantage, better than any ranged attack Hayate has outside of his abysmally slow charge guard breaks which give him a whopping +1).
I suppose you could say Hayate is better simply because of his speed though. When you've got little else but gimmicks, speed is nice to have. At least Busa has better gimmicks.