I'm definitely not arguing against that point, reading plugs is an amazing wellspring of knowledge regarding how the mixture is burning in each cylinder. The tutorials I've seen, where the band/change on the ground electrode falls for example, is really a good bit of info.A/F gauge is a tool and not an absolute. Gotta read those plugs!
The problem I have is pulling the plugs was hard enough on a cold motor in my 70 Roadrunner.
Unless my next ride has more access, and being a drag focused car it may, and the position and angle of the spark plugs may be better on the TrickFlow 270s, but if it's difficult like the Roadrunner was, I honestly can't imagine doing a hot engine plug pull outside in the summer in south Mississippi at night! I could drip so much sweat into the intake I'd hydrolock a cylinder! That's after shutting the engine off at the end of the 1320. I'd need a push or pull to a spot to do the plugs inspection.
That's a LOT to deal with.
The A/F dual wideband O2 system sure does tell a story, like a video instead of a few pictures.
There's a place for both, but I will likely have to rely more on what the O2 system tells me, unless I manage to get easier plug access.