On paper, they look good. On the battlefield they are just a bunch of apes. Just like it should be - gorillas are mighty, but helpless agaisnt armed humans.
They are overpriced, large (thus prone to being swarmed) and not as tough, as, say, a Jotun giant to justify the drawbacks.
P.S.
Dont get me wrong, I dont consider Bandar Log pathetic anymore. Not with CBM, anyway. They are quite unique and fun.