sc_burban

I purchased a '12 Suburban a few months ago replacing a 2001 I had since new. I thought I would eventually get used to the AFM active fuel management but it is horrible. Throttle response delay, additional noise resonance, added vibration throughout when v4 kicks in, lots of extra transmission shifting, differential slap, jerking heads because of when the v4 kicks to v8 you've already pressed accelerator past where you need it to be if it would have been in v8 all along.
Active Fuel Management GM Chevrolet Suburban, stay away if you pay the slightest bit of attention to how your vehicle is running. If you blast radio all the time and are just a turn key and go driver and don't pay attention to your vehicle, you probable will not have a problem with the AFM. If you have doubts, do a LONG test drive and experience all aspects of it. I wish I would have driven it longer, I would be the owner of something different.
I have yet to have it in for first service but I will bring it up but sounds like from forum no need to.
If GM would offer a switch on the dash to turn it off, I'd buy the first one!

super6

This sounds very similar to my 2009 5.3l 6speed 3.42 rear end 4x4.
The driveline slap may be a bit fixable. Big problem on the 09 s. they have to pull the slip yoke and re lube it. Covered under warranty for me.
I have had to totally change how I drive and accelerate to drive this vehicle smoothly. After 50k of driving, I have it mostly figured out, except for the throttle delay. I can't seem to get into the throttle soft enough to avoid my wife and kids heads jerking.

From what you described in your post, and what I am learning from my research, the issue isn't the AFM. Yes, the are issues with vibration and a "shutter" when it switches to v4. But the other issues are related to the poor tuning of the transmission ( GM calls this normal) and the Torque Management System. TMS is what gets turned down or off by custom tuners to increase performance, efficiency, and drivability. I am still learning what the original intent of the GM engineers was with this TMS as it seems to cause major drivablility issues with these vehicles.
Definitely go to your dealer with a detailed description of the problems you want addressed. That way there is a record of it and that will come in handy down the road.
I hope GM reads these forums and comes out with an update. Aftermarket can fix your suburban for $250-300. Why can't the company that sold you and I these $45k + trucks make them run right? Uhhhhh