How much difference in sound quality is there between the 360-12 with 2 pickups and the 370-12 with 3 pickups?

Assuming each has the same wiring, meaning that there either is or is not the .0047 inline cap to the bridge pickup in both, then:

1) In the bridge position, it is the same.
2) In the neck position, the neck and mid pickups are wired together on the 370. To my ears, it is a less distinct tone. Others really like it. I prefer just the neck pickup alone.
3) In the middle, all of the pickups are on together, with the same comment for the 370.

To that end, I have a thread about a wiring modification that I use on my guitars, to get both "vintage" and "modern" tones out of a 370 - or any other 3-pickup guitar - and that Mr. JH and crew have been gracious to allow posted:

viewtopic.php?f=2&t=7928

Thanks iiipopes!

in my 1966 370-12 MG, I made a new pickguard assembly with 3 on-off switches and 1 tone / 1 volume. that's all I need.

yes I still have the original controls assembly.