Unlike Deeaa, I've never been able to interchange necks and bodies. I've heard the same propositions others here have offered relating to the property of different fretboard materials. To my mind it doesn't make much of a difference. When you factor in all the supposedly significant variables to tone...strings, tail piece type/integrity, pickups, caps, wire harnesses(cloth!), guitar cable, od pedals, and amps, the NOS vs JJ's.....oh, and then there's the speaker!!!
Get a comfortable guitar with good physics(neck is straight, set up well etc) then you can change variable's, and therefore the sound, until the cows come home.
Having said that, I do notice a difference in FEEL of different boards. Both ebony and maple seem more comfortable to me, under my fingertips, with less friction/resistance. Never had an electric with ebony, I think I'd love it.
You be hard pressed to convince me that if you took my rig, and left everything exaclty the same, and swapped the 3/16" (that's approx 4.5mm, friends) slab under the strings, glued to the neck from rosewood to maple, that you'd change the sound. Not nearly as much as an infinitesimal turn of the tone knob would.
"It's never too late to be what you might have been" - Eliot
Guilars: '02 Heritage H-535 ASB; '04 Larrivée LV-03 w/Fishman Blend; '95 Washburn/Bourgeios D-55SW Cherokee
Amphs: Boogie DC-2; DVM/BYOC Tweed Champlifier; Marshall AS50D
Currently on Board: Ditto Looper; Boss TU-2; EB VP Jr; crybaby; DVM Spring Fever; DVM Mini Klone, Brena Effects Cali-Tremor tremolo; Strymon El Capistan