What I like about the OpenPGP card is, that I can use keys upto 4096 bits. What I like about the Feitian card is that I can add a lot of keys.
I have 2 GPG keys, one for my FreeBSD.org address, one for my Leidinger.net address. I also would like to use a ssh key just for the use with FreeBSD, and a seperate one for my own machines which is different from the FreeBSD one. And maybe I want a second ssh key for my machines which I would use outside of trusted environments. The first one to use it in trusted places, the second one to use it “on the road”. Well, ok, for the second one I should use a card only with this key. And maybe I want a 4th and 5th ssh key for systems I don’t own but have access to (if I lose the card on the road somehow, I still have a card in a trusted env to access the machines and I can lock out the lost card by removing just the keys from the authorized_keys).
With the OpenPGP card it seems I’m forced into using multiple cards (3 to 6, depending on how I want to combine the certificates), while with the Feitian one maybe two or three are enough (one GPG, one ssh-trusted and one ssh-on-the-road).