Unlike a YubiKey, the screen on both Trezor and Ledger mitigate the confused deputy/phishing attack for the purposes of FIDO U2F. I'd recommend them with usage for U2F, specifically the Ledger if you're interested in better hardware security at the expense of open-source.
I can overlook the UX issues when it’s a matter of 1-10 average signs per day and not 100s, like I have with PGP+U2F. I guess they’re all right as backup devices.
The new Nitrokeys look interesting (and not yet available) but I agree, something is missing in the market here.
I'm really interested to hear what you're doing that gives you 100s of signatures a day (or decrypts?)
I have been searching for an openpgp card replacement but I use one with a hardware pinpad, I can't imagine entering my pin 100s of times a day!