[JimD]

I like the sound of the 10 speakers in my 09 e88 (cabriolet). I have the base audio which has 25W for the 4 sets of upper range speakers and 40W for each of the two 8 inch subs. I do not listen to music real loud so this is plenty of power for me. I also used a CD with tones on it to check the frequency response. I was surprised that there is pretty good base all the way to 25 Hz. Bass level is about 3 db higher than mid range frequencies too. The bass seems less powerful than in some other cars (noticably a recent Avalon rental) but that is due to the other systems being boomy. I was a little dsappointed to find some holes in the mid to upper frequencies. For accurate reproduction, new speakers or an equalizer would be necessary.

If you, like me, are looking for an accurate system to play reasonably loud (loud enough you can't talk over it but not painful or objectionable to people outside your car) or less, I think the base 10 speaker system is enough. The premium adds more power and presumably better speakers. I haven't listened or measured it so I can't comment on its accuracy.

Jim