i also ordered without the sport pkg..simply because i didn't want to make the ride any stiffer... especially since i was planning on swapping out the 18s for 20s later on...

i am running 20s now and it's not bad at all... yes, 18s in general will give you a softer ride when compared to 20s or even 19s.. but in your case these 18s are run flats which are stiffer than normal 18s... and swapping them out to non-run flat 19s or 20s may not bring much of a difference in the ride...

i would do it... but don't get rid of your original 18s just in case you want to go back!!

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