I first got certified in hantu .... in 1998 .... 
people claim there's nothing to see there, but back in the
pre-land reclaimation days, and before hordes of irresponsible
instructors let their rampaging students demolish the corals to
rubble, there were a lot of things to see there .... huge heads of
anemones with clownfishes, groupers underneath the ledges,
patrolling batfishes, a bamboo shark, and the clowning glory, a sea
turtle !!!!!! ......(the famous 3 legged one ....), seen it all at
hantu before
and I dove the hantu/sudong wreck quite a few times before, good
place for wreck dive training, not haunted like the sister's island
one ... 
I would say, if you can get certified at hantu, you can dive
everywhere ... the vis is sometimes pretty bad, and the currents, a
little out from the ledge can be disorientating, it's the best
place to train fundamentals like navigation (VERY VERY VERY
important, a sadly neglected skill nowadays)
and when you finally go for a leisure dive at a place with great
vis ... you'll appreciate things so much more ... 