I changed the plugs myself 2 or 3 weekends ago, and with the TxStig puller it was really not that bad at all. I used a long screwdriver as a "lever" to pull out the plugs using the puller, and it all went easier than I expected.
Before changing the plugs I frequently hear what sounds like engine knocking on throttle tip-in (regardless of brand of gas, warm/cold engine, etc.). With the new plugs the knocking on tip-in seem to have gone away.
2008 6MT M3 sedan