I love Ovangkol and Bloodwood. They are a bit outside the ordinary channels but sound wonderful. Ovangkol is dark gold/brown with some red highlights. Very warm sounding while maintaining defination. Very durable. Bloodwood is , well reddish brown. Very warm, rounded sound... kind of dark. Again, very durable.
I have had 2 custom fretless with these boards and loved them both (I just sold the bloodwood one to pay for my new Bongo ) .
When it all comes down to it, it is more an issue of YOU. What do you like, what does your playing style dictate, and as Bovine put it, what is YOUR tone. If you like it and it sounds good, it doesn't matter.
ebony's smooth and hard as a rock. Even if you use steel roundwounds, it won't be easily marked. Ebonol is much better in this part. Very hard, a LOT cheaper, and almost the same sound, maybe a bit darker or dryer.
Rosewood is very soft and muddy and you will see soon enough literally pieces of your fretboard stuck between the string windings.
I haven't tried any yet ...maybe it'd be about time that I do so... I have to go help a friend to get a good decent first bass .. I'll some try MMfretless then