Hi - I stayed at Sipadan Water Village two years ago at the beginning of last year and at SMART last year - in the water bungalows.
When I stayed at SWV I remember thinking that the rooms were the biggest I have even seen at a dive op. They were huge! Also had a decent sized deck which you share with the room next door though it is separated by dense pot plants. There is no air-con but it feels cool anyway. I think there are single chalets if you want to get them but they were fully booked at the time. The restaurant and bar are also nicely set out and quite large. I would say that it was one of the nicest dive accomodations I have been to.
However I do have to say that after visiting SMART water bungalows. SWV accommodation did seem a bit dated and older (SMART was brand new at the time). We went over to SWV for a drink at the bar though as they did cocktails - still nice, but next time I would recommend booking early for SMART. Though if I couldn't get SMART I would still be more than happy staying at SWV.
If I remember correctly SWV rotates their dive guides so you get a different guide every day. The quality of guiding was very variable when I went - some people were really good and some people where just awful and didn't point out a damn thing and had us rushing around to find the elusive baracuda schools - making us all really tired and annoyed. The dive groups were quite big and I seem to remember there being up to 10 people per guide. I do remember Jimmy being very good though - he took us on some of our best dives ever and I had him for one sunset dive where we saw so many things - the mating mandarin fish of course, baby broadclub cuttle fish, coral pipefish, baby batfish, ornate ghost pipefish, ghost hairy crabs on the coral etc etc etc! It was great!
Have to say that I didn't think the Mabul Water Village dive guides were that great when I went. Perhaps they have gotten better since then, it's just that no one stood out.
I would recommend jumping in yourself for a shore dive on their housereef if you like macrostuff. It was just great being able to have time to photograph the little things without the large groups being around!
Have fun diving Sipadan!