I've had several pieces successfully modded. Higher quality lower jitter clocks, increased power supply regulation, and for a DEQX transformer coupled analog output stages made staggering improvements.

I've not done the same with my M gear, but IME it'd be wrong to write off reputable modders as nothing more than personal preferences.

Yes, an 861v4 shouldn't need upgrading, but, when you consider how aged it is inside it's not unreasonable to think that it might benefit from more state of the current art additions.

DirecTV HR21, Ram modded Oppo 93, JRiver MC17 on Win7 wi/SSD, Empirical Audio Ultraclock Offramp, 861v6, Bryston 28B SST2 amps, Salk 12" Soundscapes with Dueland caps, RAM modded Audyssey Balanced Pro, Lumagen Radiance, MarantzS4