Black Crypt uses EHB and special copper effects.
There was a special version of A10 Tank Killer that used HAM.
EHB is VERY usable from a programmers perspective. The hardest thing is remapping the colors of existing pictures/bitmaps. Most of the 256 color VGA "ports" to the Amiga should have used this mode but the programmers were just too lazy. HAM is trickier to use. It is not good for most types of games but not a problem at all for some.