I agree 110% with xariatay after just having returned from Sipadan...this after being in North Sulawesi one month earlier. Sipadan is different - not necessarily 'better' - just 'different'. Certainly fantastic for big fish - 25 or so Turtles and White Tips on every dive....huge schools of 1-2000 Barracuda....school of Big Eye Trevally with the odd Giant Trevally cruising through. We did 3 days diving (14 dives) straight at Sipadan (highly unusual - we had Ministerial approval) but we didn't have great visibility, and after being built up to the expect the 'best' diving in the world, I was maybe just a tiny bit underwhelmed by the diving at Sipadan.....Just a weeny bit. It really did lack colour compared to the soft corals; gorgonian fans; red sea whips and yellow tunicates that cover the walls at Bunaken Marine Park.....and the soft corals at Beqa Lagoon Fiji will always be heard to beat.
We dived Turtle Tomb which was just amazing and I did enjoy seeing fish everywhere...just walking on the pier and Sipadan you see Napoleon Wrasse, Great Barracuda; Blue Fin Trevally and Swallowtail Dart swimming by. But the coral has seen some damage over the years - we found superb patches of hard coral interspersed with large meadows of dead coral (blasting years ago I suspect). Mabul has some good muck diving, but we had great macro life at Siladen and Bunaken in blue water with 25 metre vis! Still, I did get to see my first Giant Frogfish and the fish life at Kapalai House reef was amazing.
So, for my money, Sipadan won't be an anticlimax - just another enriching experience in this amazing sport we all are so lucky to enjoy. Every dive is a great dive - some are better than others and you will certainly enjoy Sipadan.....
I didn't get to dive Lankayan, but was told by the locals that the diving is similar to what's on offer at Mabul. I'm not sure that Lankayan would offer enough to my group - we've been really spoilt! BTW - best resort I saw was SMART water village. Kapalai was great, but just too hot with very little shade available. Full report to follow.