Personally I've found BMW's have the worst sounding standard systems of all their competitors, especially in Europe where we don't get the business system as standard. My Mercedes which has just gone back had the standard system and it sounded great. The F11 I had before with the standard system really was poor as was the F31 I test drove. On the E60, E92 and X5 I owned I went for the business sound system upgrade. This will be my first time going for HK.
I've got a Hertz Kia Ceed at the moment and I think it's sound system is great.