We stayed at MER last fall. You will LOVE it.
You probably already know you have to pay in advance for some things, but you can pay your bill for any extras (additional dives, T-shirts, beers) at the end of the trip. I was surprised to find that they would (probably) be able to accept payment by credit card (not on the island, but after they bring you back to Sorong, where they have an office or at least some helpers). We were glad to discover that because I really did not want to be walking around Indonesia with a pocket full of dollars or euros cash (you should confirm this with their agent first, though, before you reply on my experience).
The resort is very nice. We stayed in water cottage #5, which (I think) has the best view (it's the one on the end, so is even more isolated than most others). I would ask for that one if it's available. Don't expect too much from the air con, but the fans work well enough to keep things cool enough. Nothing to do there but dive and relax, but you already know that.
The boat ride to/from Sorong was a bit longer than I had expected, and their regular boat was down for maintenance, so we used slightly smaller boats for that. Not a big deal, but unless something has changed, don't be surprised by that.
Sorong won't be a highlight of the trip, but you'll survive it OK. Be prepared to be a little flexible for all the travel arrangements. If you're coming straight from Canada, via Jakarta, I highly recommend the Jakarta Airport Transit Hotel, even if it's only for a few hours to nap and shower - it's not exactly luxurious, but is clean enough and good enough and made a big difference in how we felt the next 24 hours (it'll take half a day to fly to Sorong, using that painfully early Express Air flight, then it will take a while longer to get to the island - they were having trouble obtaining fuel for the boat when we were there, so our boat was delayed, and we didn't arrive at MER until about 11:00 at night).
Yes, it's incredibly expensive. Yes, it's a loooooooong way from anything and it takes a lot of time and effort to get there. It may be a crazy thing to do.
I was glad we did it. It was worth the cost to me. I would go again in a heartbeat (if I could afford it).
Have fun. Feel free to PM me if you have any specific questions.