Now Bob metions it, I've done what you might call a variable controlled experiment on this (nothing to bobs 20something years of experience, but its my 2p anyway).
I have a gimp guitar, called frankenstien, that started life as a PoS 100£ job (a hondo, no less). I've changed nearly everything on it, including the body. When I changed the body I took the laquer off the neck and the paint out of the heel and still the guitar sounds the fricken same. The change was from ply wood to alder. Nothing of significance happened to the sound.
The neck join is 4 screws, and its very tightly screwed wood:wood contact but there are gaps between the neck and the body at the sides (i.e. its not well coupled) and it has a strat style trem.
Try it though, and decide for yourself. Learning from experience > learning from a net forum!