Congratulations, and I wish you will enjoy the car even more
On my previous petrol BMW I had to replace all the 6 ignition coils because they were permanently dying. Dealer said, this is because of fuel quality, change them to Bosch and forget the shudder, so I did.
As for quality and specifics we have summer and winter diesel too, and petrol is 92, 95 and 98. Some branded guys like BP or Shell are selling their own ultra-super-something in top of the traditional, but no difference detected except price. However in large cities fuel is considered to be of better quality than on the countryside from an uncle sitting in a tin booth in a middle of nowhere)
But OK, great you have it fixed. Maybe you post some pics, please.
Good luck