I'm glad to see somebody is getting some data on this, I feel bad memory is one of the most underrated issues in computing generally. I'd like to see a more detailed writeup on this, like a short whitepaper.
I was recently searching for NiMH charging ICs, turns out they basically don't exist. Most devices which charge their NiMH batteries implement low CC charging, which is slow. It's a shame, because NiMH batteries do have their advantages (safety, ease of finding replacements, etc.) and can be recharged fairly quickly if the charger is smart enough.