Just turned over 284K on my 2007 Tahoe. Bought it at 147K in 2017. It was a State Department of Justice unmarked surveillance vehicle (found that out after I bought it). It has been been all over and driven almost every day...to east TX once, WA once, NV, CO, and KS numerous times (from Northern CA). I religiously maintain routine maintenance between every 5000 and where the onboard computer says 25% oil life left (usually about 7000-7500). I deal with any issues that come up as soon as I can, and it is still a solid truck.
I still have AFM active, and have had no problems with that at all. It DOES burn a bit of oil...supposedly there are improved valve covers that might help that (saw something about that in another post on here a while back). I had a leaky rear main seal, and the oil pan seal is leaky. Fixed the rear main during the transmission change, and plan on fixing the oil pan on one of my upcoming oil changes. I have replaced the transfer case and the transmission within the last two years (not together), and have a contingency fund saved up for an engine replacement when it goes. I have no knocks, pings, or bad sounds coming from the hood. The front running gear is starting to creak a little bit...I've told my mechanic that it sounds like perhaps some worn bushings or spring brackets, but he so far hasn't been able to find the source. I wish I had a lift so I could take the weight off it and start pulling and poking around till I find it, but oh well...
I LOVE this truck, and have it set up just how I like it (radios and emergency response gear), and I don't want to outfit a newer model until I freakin' have to, so I plan on running it forever, or until the sub-systems just give out on it and I can't bring it back to life.