Some of them can be neck heavy, but there are a ton of people who play them and are comfortable with the ergonomics. Most will generally say that a wide 4 strap will help prevent neck dive and keep that bass in whatever position you put it into.
The good thing with a used Alembic is that they hold their used resale value really well. If you grab it, play it for awhile and then decide you'd prefer a different body shape, electronics package, etc., you're gonna end up getting your money back when you sell it
(assuming you paid a reasonable amount for it when you purchased it).
