OK, so it wasn't just my coding ineptitude that prevented me from getting the block data? Ha!
No, it wasn't
I'm looking forward to seeing what you can get done.
Check out my new public AntPool block data API, hopefully you will be able to extract some nice pools stats from here and integrate them with your global pool surveys. With about 25% of the global hashrate, I guess it can improve stats quality.
Now everyone can scrape block data easily and without the hassle of authentication.