I loved Heron Island (I was there a year ago), but as Jac747 said, it's a low key place - and not to everyone's taste. Here's my review from Tripadvisor:

"Although Heron Island Resort will not suit everyone, I thought it was a wonderful place. It is a very friendly, low-key resort where staff and most guests celebrate the diversity of, and respect, the wildlife. It won't suit everyone because, despite the high prices, most of the accommodation is closer to 3* (and at the upper end, 4*). There is no air conditioning (although it wasn't needed because there are strong breezes), few "energy-guzzling" devices (no TVs in the rooms, no telephones, no gymnasium), no "evening disco", etc. There are no screens (but the bitting bug population is relatively low - but still exists). In November, you share the island with about 150,000 nesting birds, which make a lot of noise and probably will poop on you at least once. The mostly young staff works very hard and tries to please, but they aren't always the most professional.

But this is exactly the place I wanted to be. Having to wash off the bird droppings was a price worth paying in order to watch baby chicks hatch in the tree outside my room (they seemed to visibly grow from day to day). I'd rather spend several hours on the shore at night watching turtles lay eggs than attend a disco. I'd rather wear earplugs to drown out the oddly ghostlike sounds of the nesting mutton birds than have to wear ear plugs to drown out my neighbour's TV. I'd rather eat very high quality food (in relatively small portions) than piles of mediocre food. And the diving and snorkelling were spectacular.

Also, I was very comfortable there as a single traveller. The guests were very friendly and interesting. It was easy to talk to others, and many people went out of their way to include me in conversations, activities and meals.

My only complaint is that I wish they had made it clearer in their literature that the per-day price did not include most drinks (not even coffee, unless you were willing to drink instant coffee). They offered juice and water for free at breakfast, and water at lunch and dinner (plus tea and instant coffee). Otherwise you had to pay extra for the drinks (alcoholic and non-alcoholic). I can understand why - they have to ship everything over from the mainland, and ship all of the waste back (and the place is very expensive to run). This policy also limits the amount of littering (you don't see plastic cups abandoned all over the place, like you see at truly all-inclusive resorts). Still, I'd prefer it if they made this clearer (or included a few free "drink" tickets in the price of the accommodation).

This is a minor complaint, though, and I'd highly recommend the resort to people who are looking for the kind of experience described above. Heron Island ranks at the top of my list of extraordinary holidays."

It's easy to catch a flight from Brisbane to Gladstone, and then you can either take the launch (several hours in choppy seas; some find it a bit nauseating) or indulge in an expensive 1/2 hour helicopter ride.