nevermind, it is of course your choice. We would have been happy to see a new user though .
About openpgp: mh, I guess I read wrong on their site, but still this blog post that is linked on their site suggests, that openpgp is still not implemented in a common and fully functional fashion and some fuctions are in beta.
The OnlyKey have surely some interesting features. I still would say it is just a design decision. I am not sure, whether a pinpad is necessarily better. A party which is able to insert a keylogger into your device and steal your nitrokey is probably able to look over your shoulder while you type in the pin of your onlykey as well.
On the other hand for the onlykey you must choose pin greater than 6 characters, as 6^6 combinations are far less than 10^6 on a number-based userpin for the nitrokey (you can choose a character-based pin on nitrokey as well, which increases the possible combinations a lot). Until now I did not find out what happens if an attacker tries a brute force method on the onlykey. But it looks like a brute force attack is possible as there is no limitation mentioned in the user manual.
As for the Nitrokey the key got deleted if the pin is typed in wrong too often. In the case of onlykey the attacker even knows, that she/he must only try combination of the six keys. For the Nitrokey the possible set is much higher (and key gots deleted anyway, as I said ).
I do not want to lead this to far. What I want to say: it is difficult to design a key with a really secure pinpad without making the stick to fat. The six button solution is surely a good idea, but it is not too convincing if you think about it.
PS: I am sorry, that I did not write this before. I found the site of onlykey a bit confusing…