ok alembic nuts,let me just say this from experience in having these different basses.
without a shadow of a doubt the Orion i have is the warmest sounding bass i have. next is the persuader.the persuader is older, and has about 1/3 of the PJ pickups are set in mahoghany.
yes the tone is not near as bright than, my all maple essence,or my maple-p/heart neck thru, all walnut 20th anniversary. nor should it!!! those pickups are entirely set in maple(which is a seriously brigther sound). the tone is NOT different and/or superior because my Orion is a setneck. thats a load of crap. its preference, i believe you need some warm to your sound,your bass is made of wood not graphite ,;) i just slapped on a set of Dean Markley, sr2000 Will Lee strings and you wouldnt believe the highs i get out of my reflex mounted 18-inch celestion 250.
it will never be as bright as my all maple basses nor do i want that.
everyone do themselves a favour. Google search bass body woods and click on the Warmoth building site. there they have a whole list and pics of body woods,and,a tone-meter,for each one. compare the brightness of the maple to the mahoghany.
then reconsider your thoughts about tone difference between set necks and neck thru.even alembic tells us the wood make the difference not how its constructed.one example, alembics own tribute guitar. its not neckthru. thats why they put a thick piece of coco bolo on it, right!!! enjoy everyone!