In my 328, Bosch plugs cause misfires, stumbling, ultra-rich running, etc. They were awful. Replaced with OE NGK "Laser" plugs and never once had a problem. I now use a different temperature range (over 16psi vs 6.5psi at the time), but still only NGK OE.
I refuse to put Bosch in anything now, they even made my Honda lawnmower struggle and sputter (to the point of stalling), yet replaced with a Denso and I can now cut grass an inch taller than what made the Bosch plug stall, without issue. And no, no other changes, not even the gasoline.