When my alternator was dying, the car would spaz out. Clock dying (now works once every six months for about 5 seconds haha), HICAS going spastic, struggling to start.
2nd hand alternator and it was sweet. I should get the old one rebuilt.
BNR32s are very sensitive to voltage drops.
The larger capacity alternator means you can put more load on the system (e.g. pumps, big audio, fridge, bazillion neons, etc.).
That alternator you got is very expensive.