OTP tokens are great. I'm a proponent of the physical token. My original FFXI token from 2008(?) was just replaced a few months ago. One of the original tokens that my wife got from the FFXIV 1.0 release is still working just fine. I have it on a badge pull connected to my monitor. I'll never use it away from my PC, so I keep it there. Doesn't get lost. None of those "I replaced my cell phone and didn't disconnect the app from my FFXIV account" problems either.

I don't like the app since my cell phone leaves the house. I could see that being misplaced, dropped, broken, etc. However, NOT using the OTP is asking for trouble.