Sustain blocks

[zn_bassman]

I've seen much discussion on this, and I'm looking for feedback from owners as follows:
 
1. On a set-neck, how much sustain does a block add?
 
2. Same re: neck-thru?
 
3. What's the effect on the tone (I understand it tends to add brightness)?
 
4. Has anybody tried a block made of ebony or another deep tonewood? What's the story on such - does it add any bassiness/depth?

[richbass939]

Zvi, here's a thread from last summer about sustain blocks.
http://club.alembic.com/Images/449/18857.html?1120101708
Rich

[zn_bassman]

Thanks Rich. I've seen that one already. What I'm looking for is stories from the field, especially relating to the specific questions I posted. I'm considering some mods to my 2 current Alembics, plus thinking ahead to a future project or 2.