Not wishing to rain on the OP's parade but I've just been reading EVO's first impressions of the G20 330i M-Sport and suffice to say they're more than a touch lukewarm about it. I suppose to some extent it depends on what you want from a car and in fairness I know other initial reviews have been positive; however, EVO's summary is "too much focus on tech, not enough on driving" and frankly that would have me running for the hills (or at least waiting to have a test drive so I could judge for myself before placing an order).
They were however more positive about their brief drive in an M340i prototype and suggest that model may be worth the wait - perhaps all is not yet lost then!