Re: it's too big
It's too small for me.
As you said, it's better to have e.g. a surface and the keyboard on there.
Even that's not really good. I have large hands and typing (properly) on anything smaller than a standard size keyboard is an absolute pain - I can't fit my hands on it and reach all the right keys with the right fingers.
I'd love one of these but I can't help but feel that I would be reduced to pecking at the keyboard with index fingers