Trezor does not work on iPhone. They refuse to pay licensing fees to Apple I think. I would never keep private keys for more than a few bitcoin on an insecure device like a phone. You could just use Trezor with your laptop while on vacation. Trezor works with OS X 10.8 or better just not on iPhone.
I'm just wondering why I should trust a Trezor, as I trust Armory. With Armory, it's software on GitHub that I compile. With Trezor, it's hardware and I have no idea what they put into the hardware and I don't know much about hardware. So I'm kind of scared of it.
Are there any software alternatives to Armory that use SPV (so I don't have to carry the blockchain with me) but also have determinstic wallets (for one backup only)?