Can't comment on the 330 personally, but agreed that as per int forums the NGK seem the choice. My 318i, chowed the NGKs so I only used Bosch on the 318i and used the same on the 330i when I changed them.
Be interested to see what / how the NGK rate in the 330i, however they are big money IIRC when compared with the bosch. That said always rated NGK plugs in my Nissans. The wifes Opel only likes Champions so who actually knows - sorry I'm rambling now !