Howdy Terrapinz, Welcome to the Forums!
All the bikes you mentioned are nice. When you get into the even higher end stuff, you're mostly paying for weight reduction and somewhat better components. And when you wear something out, which you will eventually do anyway, you can always replace it with a better component then. If you're not racing, all the bikes you mentioned would be great rides. That's my 2 cents anyway. Happy Riding!