I lived in Ubud for 3+ months this year, spent on and off time in Canggu during that time. I just returned to Bali and am moving into a long-term rental house in Canggu.
My two cents:
I love Ubud. It has a great coworking space, Hubud, and a pretty established digital nomad/online entrepreneur community there.
I love the yoga and amazing healthy restaurant scene there. I'm a total hippie myself. So yeah, definitely an awesome place. And one, that needs a while to get to know, so as a tourist not as fun, but to live really great.
But: You are an hour scooter drive away from the beach and surf. It rains much more in Ubud in rainy season. Traffic is a bitch most of the time in town. And Canggu is just more chilled out. But it guess it's a matter of preference. I dont think one is better than the other. You can also get a house outside of Ubud in the ricefields, where it's quiet.
I find 3G and wifi in cafes etc better in Canggu too. Ubud is lagging a bit behind in that department, but Hubud has great speeds now.
There is a lot of yoga in Canggu now too, pleeenty. Awesome cafes and restaurants.
The online entrepreneur community is not quite properly established yet, but I would like to change that.. there is a cool coworking space, Dojo Bali, which just took over Salty Volt. Let's see what these guys are doing with the space, apparently they have big plans.
The way I will keep it from now on: Have a house in Canggu and then go to Ubud every other week or so.
Let me know if you have any further questions!