Nowt wrong with Giant Mike. Also GT aint bad either i bought my GF an GT Avalanche. I also Own a Kona :p The Giant is a fantastic bike tho IME, it's very stiff and very very fast.
so all of the above (including the Giant) are possible choices. My pick would be the Giant, it uses very light aluminium (6013 Fluid Formed) this makes it light and very strong.
:p i'm very sensetive when it comes to Giant Mike :)
I like the look of the Kona to be honest. However bare in mind that Giants 6013 Fluidformed aluminium is probably some of the lightest and strongest aluminium you can get.
Because they are the biggest manufacturer in the world they have the facillities to develope new technologies like this. I mean their carbon frame building is regarded as some of the best in the world (they make the majority of the carbon frames on the market including specialized).