I say go with the Corsair.
I have the K90 and the hybrid board doesn't bother. Unless you use the function keys a LOT, it probably won't bother you either. But some people have reported that it's jarring for them...
Honestly, order the Corsair K60 on Amazon and just return it if you don't like it. That's what i do these days, I just order everything on Amazon and try it out...make use of their amazing return policy. Even if they charge a restocking fee, go to the live chat and ask them to remove it...they ALWAYS will.
I'd wager that most people on the net (not this forum specifically) who are suggesting the Leopold haven't used both keyboards. I have and I prefer the K90 (about the same as the K60).