Another vote for the Rune - I love mine.
Large, with 36 Van RC2's, Reverb, XT brakes, Easton Havoc wheels, Hans Dampf tyres, CCDBa, Atlas cranks, X9 1x10 etc it weighs in at 33lbs on the nose. It genuinely doesn't feel like a heavy bike to ride and climbs far better than it should but is definitely a bike that prefers the downs to the ups.
The CCDBa is pretty damn good although there is the opportunity to make it ride horribly by fiddling too much as I did. I've just reduced the air volume and gone back to the base settings and its much better (although I still prefer my rebound slightly slower than recomended).
The only thing that I have found is that it can be a bit of a handful on really tight corners due to it being pretty slack and long. I run mine in the neutral setting (65.5 degree head angle).
I also looked at the Covert and liked it, but the medium was too small and I didn't like the look of the large. I know I'll probably get flamed for saying that but this was the most that I have ever spent on a bike and I wanted something that rode well and I liked the look of. The Covert felt a bit more playful due to being a tad shorter and steeper but not quite as good on the steep or fast stuff.
To be honest, all of the bikes listed are really good. It comes down to how much you want to spend and what you like the look of I guess.