OP: I want to buy a bike, my budget is $3000
Everyone else: You don't need a bike that's $3000.
Who gives a poo what the OP needs, he has a $3000 budget, let him buy a nice bike if he wants one.
As others have said, most of the bikes you mentioned are TT/Tri bikes...those are fine, but they're more geared for 40km at a time as opposed to an all day jaunt with your bike buds.
If you like the Cannondale Slice, you might want to check out the Supersix, Evo, or Caad 10 ... if you'd like an even more relaxed geometry, the Synapse would also be a good choice.
Something like this would get you rolling under your budget and its a helluva nice bike:
http://www.cannondale.com/catalog/pr.../category/916/
Or if you want to hit your $3600 price point, you can start looking at the Ultegra and Red fitted bikes:
http://www.cannondale.com/catalog/pr.../category/916/