I did this. I came to the realisation that Gouken has serious holes and limitations and after the OHN nationals in Australia last year, moved onto Akuma. I still use Gouken and was harbouring some hope for his Super incarnation though that turned out to be a disappointment. Gouken is a middle tier character and that implies that you can use him well.
Demon flip options carry over to a small degree though they’re really completely different. The biggest hurdle will be managing your health as Akuma compares poorly to Gouken in this regard. Still, Akuma has a wealth of tools and options that Gouken just plain doesn’t have in addition to you being welcomed into the wonderful world of hitconfirms and, yes, a cancellable reversal. Resets, untechable knockdowns, FADC combos, kara grabs, juggles, mix-ups. Akuma has it all.
You’ll miss Gouken’s very viable Ultra though you’ll be surprised at how many ways Akuma’s can be landed. Oh and speed. Akuma has it in spades.
Akuma enjoys comfortable match-ups, but noone is free due to you having to manage your health properly. His harder match-ups can be nightmarish but you’re still equipped to wreck house.
Is Akuma a better character? I’d say yes, definitely. Is Gouken a good character? I say yes, he’s okay - provided you understand him properly and have good defense and a solid understanding of the game’s fundamentals. Gouken is fun to use but he has trouble once people mix-up their offence when in close. Conversely, once Gouken sinks his teeth in, he chews off gigantic chunks of life. Problem is, at high levels the former usually occurs before the latter.