I generally do more frequent oil changes than recommended by the manufacturer (BMW and Porsche both specify intervals that are too long for my comfort), but I like to use oil analysis during my first few changes to get a sense of how well the oil is holding up during my typical use cycle. If the oil analysis shows low contamination and lots of remaining additives, I extend the interval a bit for the next change.
My E46 M3, also with TWS 10W60 fill, the sweet spot was around 7500 miles, which just happened to be one change between every dealer change.
Here is a grab from my first oil analysis on the E60 M5, at 6300 miles (5300 miles on the oil).
