When should I get my first oil change?

[np2004]

I have had my 4.8i for a bit over a month now with around 1400 miles of non stop fun on her! I get in her and dont want to get out I never thought a SUV/SAV could be so much fun to drive especially in the twisties! I know the normal service oil change interval paid by BMW is 15,000 miles but when normally do most X5 owners get their first oil change since this is the time when the most amount of sediments will be in the oil? Also on my 04 330ci I do it every 7500 miles after I did the first oil change can I keep that the same or should it be done sooner in the X5? I know there are always debates and arguments that doing oil changes it btwn intervals is not needed since BMW uses synthetic oil so its just a waste of money but wanted feedback from current owners.