I started using queri.ac not so long ago, was a yubnub.org fan, and still am a BIG fan, but the fact that all the commands you create must be public and that you can't delete them makes me very prudent.
With queri.ac I can create as many as I want and keep them private (eg.: in case I've made a stupid mistake)
PS: I still use yubnub though queriac (eg: like this one tr2 =)
... because yubnub is YUBNUB! The 1st and copied