This is an ironic thread……As a CAAD9 5 owner myself
The owner of a local bike store recently let me ride a stunning Colnago, a Cannondale and a Giant Defy Carbon and a Giant Defy entry level road bike.
I have only been cycling for about 20 years, but other than the major difference between the Tiagra component set on the lower level bike, all the others with the 105 set felt pretty much the same to me once I was actually riding.
Its not like I buy a new bike every year so if the Colnago was clearly better I would have went for it.
There was nothing to envy.