i also thought about it for awhile before finally placing my 08 order..

i examined both systems and although i noticed a difference in the upgrade it wasn't the "wow, i must get the upgrade!" feeling i was expecting..

the stock seemed more than enough... i have an upgraded system in my Landcruiser and the stock x5 sounded better...(maybe because it offers more speakers and two subs!)

i just couldn't justify the $1850 for the upgrade...

but if you're planning on swapping out speakers later, and upgrading the amp separately then i would opt for the upgraded system. You will end up spending the same amount for the same results... (better to have it installed by BMW than some third-party that will rip things apart)

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2012 X5 50i M-Sport
2014 X3 35i M-Sport