The Killer is marketed as a pad for FPS fans, while the Winner is geared towards RPG players.  Nova differentiates the two pads in size only: the Winner (225 x 225 mm) is much smaller than it's bigger brother (320 x 320mm).  Both pads are shaped the same, & both sport the plush "alerting frame," which helps you to tell that you're nearing the edge of your pad without looking at it. 

Nova's Killer with a Logitech MX500

Nova's Winner with the same MX500

Both pads also sport the same backing, which I can only describe as similar to a high-strength version of the static window decals.  (Hrmmm... maybe it's the same stuff those Fathead guys are using....)  Once I laid the Killer out on my desk, that puppy wasn't going anywhere.  It's a welcome innovation after using Ratpadz for many years; yes, the Ratpadz don't move 'much,' but you can still jolt them from their feet on occasion.  The Killer & Winner simply will not budge.

You literally have to PEEL it up from the package

The highlight is a thumbprint pushed into the bottom