Just bought a Trezor hardware wallet only for NEM and the Mosaics to be safe, and I recommend everyone to do the same. I'm using the Ledger Nano S for all of my other coins but sadly NEM is still not supported on it.
I decided to buy the "old" Trezor One, I hope it was the right decision.
Although hardware wallets are considered to be secure, they have their glitches too, so always be careful and follow a common sense.
Threats will always be present,
especially if large funds, or a public individual is involved
Below an example, the hack that was developed on Mar 2017 and fixed by Trezor on Aug 2017
https://medium.com/@Zero404Cool/trezor-security-glitches-reveal-your-private-keys-761eeab03ff8