There are plenty of reviews but let me highlight a key point. This is the one that works with LastPass on your computer AND your Android phone w/NFC. If you want to secure your LastPass on your phone with a hardware key, this is the one. That's what differentiates from the YubiKey 4.

Note that I am referring to Android phone with NFC. If your phone supports mobile payments (tap your phone on payment terminal), you have NFC. Android only. As far as I know, ti does not work with the iPhone (but double-check).

LastPass has workarounds for if you don't have your key. To me, this sort of defeats the purpose but it does add a different layer of security.

I just wish this thing was a little cheaper. It doesn't seem like it should cost so much ($50).