It doesn't provide you with any feedback. Thus you don't know if it actually saved your changes.
yes, +1 for it. I clicked about 5 times on save and after that, i just refreshed a page to find it does save our data but no confirmation.
This could use feedback or confirmation such as: a message like "Great! or Success! your profile has been updated" , a form reset, a plus sign changed to a check mark, etc. I clicked Save about 3 times, too.
Another case I found is "submit". Sometimes I press "submit" and it just takes a few seconds for the page to show me the next sentences. However, because I don't get any feedback on the process, I tend to click again because I think I haven't properly pressed the button. This completely screws up the submission.

Love the new visual response to submitting your sentences!

Whoops, meant to close this one when I submitted the above change.
https://github.com/mozilla/voice-web/commit/c84ce400f03030a463bdc813dd3cd11516bad3b2
Most helpful comment
Love the new visual response to submitting your sentences!