Originally Posted by PA66400
Changing spark plugs is very easy, BUT you will need to invest in a particular socket (thin wall, different socket pattern from anything I've ever seen. the Bosch plugs can be bought on the internet for less than the dealer. The OEM "BMW branded" Bosch plugs are exactly the same as the non-BMW logo Bosch plugs, but not worth the extra money, unless you need a BMW and Bosch logo on the plug (the plug is made by Bosch only for the N54/N55 engine).
Many people change the oil themselves, halfway through the condition-based service indicator interval and don't reset the interval. Others here have just followed the interval and nobody who did that has ever reported catastrophic or even non-catastrophic failure - one person did this and had his car for well over 150K miles. It is worth it to invest in the spark-plug socket and the oil filter cap removal tool if you are going to do maintenance and hold onto the car for a few years. Oil change takes me literally less than 30 minutes, spark plugs less than 1 hour.
Hope this helps. You will enjoy the dramatic improvement in performance and safety and refinement over you older BMW but you will find the new car less reliable. My car history is the same as yours, basically.
Not to start the debate, just a data point: my car is at 198,000 miles on 17,000 mile OCIs (average). It's an N52 however. Runs as new.