I just replaced the calipers, rotors, and pads on my 09 Tahoe with a front and rear package from PowerStop (
link). As part of the project, I "upgraded" to a GM Dot4 fluid from my local Chevy dealer, as what was originally put in my Tahoe had been discontinued or was otherwise unavailable (Dot3 Super 11). Flushed the whole system. When I was done my brakes sucked. Spongy, had to pump the pedal several times to get firm pedal. It was like my master cylinder was loosing it's seals.
Long story short...
I researched the MSDS on my new and improved brake fluid vs. the original and found that it had a much higher viscosity than the original OEM stuff. This was causing issues with the ABS not activating properly. After some more research of other fluid's MSDS I found and installed a brake fluid by ATE (
link) which had a slightly lower viscosity than the original OEM. After fully flushing the system with the ATE fluid, my brakes are amazing!
Not sure what fluid you used but, it made a huge change in my application.
Those rotors you've picked out... they look positively Bad Ass!