InspirationDave:
It is the little critters that interests me, not really into Mr Big. But I just don't want to dive in crappy, trash laden waters.......I get a huge kick out of macro stuff, but would prefer it to be on a coral reef rather then sitting on trash.
If you love critters, Lembeh is amazing. We spent 8 days there and could easily have spent at least another week or two. But, you do have to have a different mindset than "normal" coral diving. This is muck diving at it's best. The visibility is maybe 15 ft. if you are lucky and the bottoms are usually featureless black or white sand with algae clumps, broken bits of coral, discarded rope, the occasional anemone.... They do have some coral sites in the straits, but that's not the reason to go there. The reason to go there is that for some reason a huge range of "critters" love this environment and make it their home. Every dive is a treasure hunt to see what you can find and if you are into critter behavior, the most amazing thing is to see how these creatures camouflage themselves to look like their surroundings.
It's true, there is trash in the water, but it's not overwhelming as long as you are prepared for it and what's amazing about it is the way the critters have adapted to it and made it their home. For example, we spent 5 minutes on one dive watching a coconut octopus eat a small snail. When he was done, he sank back into the sand and used one tentacle to pull a nearby plastic bag over his head so he couldn't be seen. Wow! Also, because there's so little coral, everything takes cover in whatever they can find. For example, the occasional lone anemone will be swarming with 10 or 15 anemonefish (including two or three different species in one anemone) and often a clump of Banggai cardinalfish. In that same anemone, there will be at least 5-10 anemone and cleaner shrimps and occasionally a crab or two also.
A very incomplete list of the creatures we saw in one week includes the following: Yellow, pink and purple pygmy seahorses, several varieties of regular seahorses, 5 different types of smashing and spearing mantis shrimps, ambon scorpionfish, warty, painted and giant frogfish, fingered dragonets, mandarinfish, inimicus devilfish, stargazers, crocodile flatheads, at least 5 types of snake eels, coconut octopus, wonderpus, mimic octopus, flamboyant and regular cuttlefish (flamboyant cuttlefish are unbelievably cute - they look like tiny baby elephants in tutus - hard to explain, you just have to see them to believe it) and on one night dive, a Bobbitt worm. Plus, at least 30 different varieties of nudibranchs including some we can't find in any ID book.
I've also been to Komodo and I would agree with ssra30 that it is a better "all-around" trip. You see both critters, clouds of fish and beatiful corals, and some pelagics on that trip and we'd love to go back. But if you like critters, Lembeh should also be on your list. If you go, I'd highly recommend doing what we did. Spend a week or so on the Manado side of the peninsula and dive Bunaken for the beautiful reefs and walls. Then go around to the Lembeh straits (it's a two hour+ car ride from Manado) and spend at least a few days muck-diving. You won't be sorry. If you still aren't sure whether it is worth a few days, another alternative is to base yourself wholly in Manado and do Lembeh as a day trip.