How is the DFM working for you?

[Stex]

Only miles will tell if DFM is a problem. Hope they fixed those lifters. And the DFM does have as much if not more than AFM going on mechanically. And the software and number/swiftness of decisions the ECM makes ....Tech article: 

As you probably are aware, AFM was a relatively simple system which converts a V8 engine into a four-cylinder (operationally) by deactivating four cylinders. DFM expands on this idea by installing the AFM style, spring-loaded lifters in all 16 positions so that all eight cylinders (instead of only four) can now be selectively deactivated.......Mechanically, DFM is just an extension of the earlier AFM system.

They have levers in the lifter deactivation chain. As to running smooth and cannot tell DFM is there, see this: more mechanical , 

These new DFM-equipped trucks and SUV’s will also be upgraded with what GM calls a “centrifugal pendulum absorber” in the torque converter. Essentially, this is similar to a dual mass flywheel for a manual transmission. This pendulum absorber employs coil springs mounted to a plate splined to the input shaft of the torque converter.

This pendulum device will isolate noise and vibration between the engine and the transmission. When cylinders are deactivated, the number of crankshaft rotation increases between firing pulses. A V8 firing all 8 cylinders sees 90 degrees between combustion events, while a 4 cylinder engine lengthens this to 180 degrees. That inherently less smooth operation requires additional NVH dampening.

 

https://www.enginelabs.com/engine-tech/gm-escalates-cylinder-deactivation-with-dynamic-fuel-management/

[GunnerJohn]

I notice A LOT of Engine lag form my 19 Silverado with an aftermarket exhaust When the DFM kicked in , could that be the reason? Drove my neighbors Silverado of the same year and couldn’t feel it at all. 

[Moend]

creeping on 25k miles, check engine light came on 2 days ago U0284 (Active Grill Shutter No Communication) that is about it and it is overheating if i have the plow on while going 45mph or faster.

 

[Tjeli]

It works fine and I do seem to get "slightly" better MPG with it enabled but I can feel it and hear it doing its thing.  I prefer how the truck runs with it disabled.

 

-Eli