I would guess if you've had braided brake lines on your R6 then that's why the Blade feels spongy. The only bike I've had with braided lines on was a Ducati Monster 750 and the brakes felt very immediate and not spongy in any way. My current Blade brakes feel a little spongy at the lever but it doesn't really bother me. I know that if I pulled hard enough on them I could flip the bike over its front wheel, despite the slightly soft feeling.
Red rubber grease on the pistons/seals as it will not affect the seals. A dab of copper on the back of the pads then too.
