Haven't noticed any raves about alder/ebony...
Okay, I'll rave. I have a couple of Alder/ebony basses, and they are fantastic.
plenty of alder/ebony MTD's out there. It's actually listed as one of Mike Tobias' favorite and popular combinations.
That being said, I think an ash neck with ebony fretboard is too harsh to be practical.
If you think ash/ebony is too harsh, you must REALLY not like ash/maple.
Pretty sure a balsa wood body with a bamboo neck would be a no-no...
Bamboo is REALLY hard, and makes great floors, but I don't know if it would be workable for a bass neck.
As usual, I think people are WAY over thinking the whole tone wood thing.