The Sony PSX (original Playstation) English dev docs were also pretty bad, IMO/IME. I worked at a game company in 1995-1997 where we were porting our PC title to PSX and to Saturn. I was leading the PSX project which eventually shipped and was an "OK" title (but nowhere near the then state-of-the-art IMO). The Saturn project was eventually cancelled as the team couldn't get enough performance out of the Saturn and really struggled to get much pace of development.
We were using a dev kit that I seem to recall was 3 ISA PCBs (though pictures on the internet now show only 2, so maybe my memory is faulty). There was also a "blue" physical playstation that would boot unencrypted disks, so if we were willing to go through a full CD burn cycle, you could test there, which is how we did QA and potential golden master testing, but most development was on the ISA cards.
Compilation toolchain was gcc-based, and we did almost all of our debugging with printf. :)
Most interesting to me technical tidbit: We did build our own pre-emptive interrupt system to ensure we could run the game physics engine at either 15 or 30 Hz (technically slightly less, as it was on the NTSC vertical blank). Sony support said it wasn't possible... ;)
To the extent Sony won that round of console wars, I don't think it was on the quality of documentation, at least not the English translations.