have the K70 (same but no extra buttons, more FPS gaming like). I've had one LED go out (3 months old), fortunately its some useless button i don't even know the name of (between right-windows and right-ctrl).
Look for any MMO-specified keyboards, they're the ones with all the programable buttons.
One big difference in these two is that the K95 would probably be a lot noisier to use (i have Cherry browns, specified as being one of the most silent ones in my K70).
The Logitech doesn't have Cherry switches after what i know, but are made to be silent and comes with dampenders for even lower noise, with isn't standard on the K70/K95.