First Glance:
Just received the keys in the mail and they look and feel great.
Lowered profile keys with textured surface, grip better than normal surface keys.
The keys have a nice control feel to them.
The close spacing of the keys help with movement of the fingers, a more "glide" feel than a "lift and press", which I like.
The rounded corners cut out hitting the hard edge of the regular style keys which can cause some delay in reaction.
Quickly playing on these keys, they help with location of the appropriate keys. By this I mean if you have your fingers on the regular WASD cluster and have C for crouch or R for reload, it helps you by quickly finding those different textured keys and eliminates the ever loving hitting of the wrong key and evidently getting yourself killed.
(Of course if you had these keys for the whole keyboard it would get rid of that advantage) but it's something to consider when learning a new mapped key... these could be good training keys to help you learn a new games keys.
I'll continue to play with these and give my rating later on when I've had enough time to find any flaws or concerns.
Thank you for reading, and here are the pictures (sorry for the quality)
http://imgur.com/a/yCYoa