These keys are on loan, and they are for an HHKB Pro 2, and while they are the same size, they feel more textured. So far I am liking them a lot and I am getting used to the no legends thing. I have had blank keyboards before so it isn't really that new, but still it will take a bit of time to get used to not watching the keys. I guess if that is my aim, a blank keyboard is the way to go.
The color is very slightly lighter on the blank keys but that could be due to them being brand new.
And this proves for once and for all that the Topre and HHKB keys are identical and fully interchangable, so long as they are from the same row.