Ak7

I'm looking at purchasing a 2013 ML63 with 70k km's (roughly 44k miles) on it to replace my 2014 cls550 which has 41k km's on it (roughly 25 k miles), I love my cls especially being tuned with meth injection, but as a winter car I'd rather have an suv with all the highway driving that I do.
I'm doing some research on tuning, but not finding a whole alot of people that tuned their ML63 W166.
For anyone that has tuned their ML, how is it? Reliable? Are they as tough as other M157s when it comes to tuning and pushing them to the limits?
Plan is air intakes, decat the downpipes, meth injection and tune.

Any feedback would be greatly appreciated!