That's really good, I watched one of their older videos to understand what I was getting into before I bought a Toyota a few years back. For those reading, the video is from Weber State University, they have a series of hourish long detailed videos on various automotive components including different versions of the Toyota electric transaxle and rear electric drive unit (mechanically separate but present in the AWD vehicles).

My takeaway was the same as some of the other posters here, the system is an engineering tour de force. Simpler than the gas version, proven reliability, and efficiency not too far off the theoretical limit of gas-burning drive trains.

This video cleared up my confusion and corrected my misconceptions, giving me enough knowledge to hold a one-hour discussion with an actual Toyota mechanic.

Highly recommended!

That video is what made me get a Toyota hybrid.

Seeing how simple the whole mechanism is, I totally get why the empirical reliability is so good.

Not to mention that the lecturer shows and explains things very clearly.