also just got back from Mabul. Stayed at Scuba Junkies Mabul Resort. It certainly has backpacker elements to it, but a varied clientel, I mainly dived with an older couple from Poland who were lovely, there were also other non backpackers (like myself) staying with them and generally just really nice people. luckily we had some good divers and enough to head to some sites that aren't often dived by SJ (and it looked like not dived by any of the Mabul operations either) so it more than kept me entertained. Excluding night dives which are only out the front (but among the best night dives I've done) I think i did 3 or 4 dive sites twice in 9 days, and two of those were Sipadan's Barracuda Point and The Drop Off. Secret dive site of the trip was Second Wall off Mabul, fantastic submerged reef.
I'll write up a bit more of a report later. but the short version is that everything was above average if not excellent with the resort and diving operation. would recommend to anyone, couples, groups, single travellers trying to avoid the huge cost of some of the other resorts. people were easy to meet, diving operation was competent guides varied in skills some excellent at spotting macro and had a huge amount of knowledge of marine reef flora and forna, some just spotting the 'known' items of the sites... such as Elvis.
food was good, mix of local style food and more western food. they don't serve pork or seafood at the resort, so it's either chicken or beef. I ate mainly vego options which was fine. bar is a little on the expensive side, but it's a resort, trapped market, and it's one of the nicer bars on the island, so I think the 10 RMB for beer was high, but understandable.
dynamite fishing is definately in the area. very sad to hear them (and feel a few!) throughout the dives and see very few mature reef fish on the barrier reef. It seem strange there isn't more of an effort to get blue water fish farming more prominate in the area, it seems to be ripe for it.