TL;DR: I had to wipe everything and set my phone up as a new iPhone. No restoring from backup.

When I updated my iPhone 6 to the new iOS I was very excited. I was looking forward to all the cool new things that iMessage would be able to do now, from the cool new ways to send texts (Loud, Slam, invisible ink), to the new apps that would work in iMessage, and yes, even the sticker packs.

I updated both my work phone and my personal phone and have had drastically different experiences. This blog post contains my notes on my fixing the slow typing issue in iOS 10. I hope it helps you.

• So I updated to iOS 10 over a free hotel wifi in London. Maybe that was the problem? I thought it might fix itself but no dice.
  • Fix: I updated my phone to the new release of iOS 10 (10.0.2) when I got back a week later.
  • Outcome: It seemed to make my phone better for a few hours but it still lags when typing anything.
• It was still lagging so I called Apple Support
  • Fix: They told me to backup my phone to my computer and do a full restore and that would definitely fix the problem.
  • Outcome: I did. Despite trying to delude myself that the issue wasn’t as bad, there really wasn’t any change.
• I called Apple Support back a day or so later.
  • Fix: The support person was very pleasant and had me change a few settings on the phone.
    • Under Settings > General > Accessibility > Increase Contrast, I turned on both Reduce Transparency and Darken Colors.
    • Under Settings > General > Accessibility > Reduce Motion, I turned Reduce Motion on.
  • Outcome: Neither of these made much of a difference.
  • Fix: Since we were in settings, I decided to turn off Assistive Touch (under Settings > General > Accessibility > Assistive Touch). This isn’t something everyone has on, but I gave it a try just to see what would happen.
  • Outcome: This was definitely helpful and seemed to almost cure the problem. At least, it did while I was on the phone with Apple Support.
• After a few hours, the problems were back. Not nearly as bad as before, but still there. I tried ignoring the problem for a few days but when you can’t text anyone back and you want to tweet as much as I do, you can’t ignore it for long. I started tinkering around with the iMessage apps.
  • Fix: I disabled all but two of the iMessage apps. No more Mario Run stickers for me. I had 11 or so active apps.
  • Outcome: This helped marginally but the lagging remained.

• This was really bugging the hell out of me. I would go to type an email, text, tweet and I could get only a few words down before the phone would lag and act nonresponsive. I called Apple Support back and set up a Genius Bar appointment.
  • Fix: They told me to NOT restore from the backup on my computer but rather backup to iCloud and restore the phone from iCloud and if that didn’t work, to set it up as a new phone.
  • Outcome: I restored my phone from my iCloud backup. It still has a subtle lag. Dammit.

• One day later, I am beaten. I caved and deleted everything.
  • Fix: Finally set it up as a new iPhone.
  • Outcome: Aside from having to re-download all my apps, put my password back into almost every app I own, lose all the photos on my phone as well as my most recent set of contacts, at least the typing is finally back to normal.

Conclusion: While my incremental steps were frustrating and it’s been four weeks of extreme annoyance, I’m glad I was able to finally fix the issue despite the hassle of setting up a new phone. The Genius Bar employee said that sometimes, issues can be underneath the surface and a new iOS can bring them to light. While I was annoyed to be told this in the store, I suppose there is some wisdom to that statement. I have been quite good about not losing my phone [*knocks on wood] and so have not set up a new iPhone since I got my iPhone 4S in October 2011. As inconvenient and aggravating as it is to have to set up everything again, maybe a 5 year reset is a good thing.

*These gifs were shamelessly stolen from George Tinari’s post on the new iMessage Bubble Effects post.

[UPDATE] – I’ve found the biggest difference by deleting extra Siri voices and especially extra keyboards. Keep only your main language and the emoji one and no others.