All nice rides.
I personally love the divinci Wilson if money was not a factor I would be on that right now. I ended up going with a 2011 commencal (the V3 is classed as 2012). These were the two bikes on top of my list and I cannot be happier with he commencal, as far as I have been told by commencal the V3 runs the same or very simar leverage ratio as the 2011 model, the new linkage however allows for improved square edge hits and increased pedaling efficiency. The Wilson also has a low leverage ratio and on paper their geometry seems damn good.
There are a few guys on here running the wilsons so even shoot a PM over to them and they might be able to give you some direct feed back.
The lappiere well it's a lappiere brilliant lookin and probably works just as brilliant, the rotating BB design reduces/stop chain slack and growth (as far as I'm aware) which can have obvious advantages on the trail. I don't know if they are in AUS and getting parts/warranty and work done might be a issue or at least a lengthy process.
The demo 8 has super short stays and a long front end, this tends to call for a more forward positioned ride, this is not a bad thing just something to note. The demos have clearly gone through a massive development in the last few years and their bikes seem to be living up to it.
With all that been said the giant riders have been putting up awesome results and a glory will work out much cheaper, however they definitely don't have the same aesthetic appeal.
Ideally the bikes you listed have quite different designs and to say one is better than the other is a hard task as they all can be ridden to a WC podium and they all will suit different riders.
As per usual try jump on as many as you can, even other bikes to help sort out what you like and dont like in a bike.
If I had say 8-9 k to spend I'd grab something around 6-7k and spend the rest on riding clinics or training tools.
