Having used the Trezor and the Ledger Nano S, I felt the Trezor is a better experience. It currently doesn't all the coins that the nano does, but I felt the UX is much better, and not needing to add/remove apps to look at the different coins.
I do like the annotation of the transactions, and the displaying of info on the Trezor screen to confirm as a mitigation for javascript attacks that change the wallet addresses when sending.