I'm gonna have to vote for Trezor, definitively proved its worth to me. Before I bought a Trezor I was using a raspberry pi cold storage. Trezor works so much better than using a computer/notebook dedicated to acting as a wallet. I don't lose any sleep over using a Trezor because my seeds is written down safely and nothing can happen to it, I could burn and smash my trezor and still be able to recover my funds. The form factor is great to, with a netbook I doubt you want to carry that to a shop, and once more wallets support trezor on mobile systems it will be perfect solution.