On "Collections" moving the bottom right slider doesn't resize the cells.
On "Containers", dragging the blue square is pretty buggy.
There are others too.
That kind of stuff would be a problem for me.
I was about to point out what other people have too, why would you store CC data? and if you did, you wouldn't even consider storing it in the cloud anyway.
Such as deep integration with other services, which you hint at with the use of 'pocket'.