Has anyone tried the digitech BNX3 or any other product similar.

There has been a bit of discussion of the Line 6 Bass Pod (which doesn't have the workstation features of the BNX3). See
 
http://club.alembicguitars.net/Images/449/3132.html#POST4096
 
Although there are many favourable reviews of the Bass Pod elsewhere - it seems that Alembicians are generally not impressed and prefer the Alembic preamps.