Just wanted to clarify a few things about Cannondale (since I work pt at a C-dale dealer).

The proprietary parts that require special tools are generally found in the mountain bike line (e.g. Headshok and Lefty forks).
The larger-than 1 1/8" diameter of the headtubes on these bikes also means you are also somewhat limited on stem-selection. If you stay away from suspension forks you have no worries there.

Certain C-dale road bikes DO have integrated headsets and bottom brackets, however, this is becoming more common in the industry and is seen on many other bike brands as well.

An integrated headset is still...just a head set. The integrated headset in my C-dale road bike is Campy. The headsets offered on the current C-dale touring bikes are Cane Creek(and not integrated to my knowledge). I'm not a huge fan of the whole integration-trend, but at least I know that replacement parts are fairly easy to find.

The integrated crankset/bottom bracket is (at this time) only found on the super high-end CAAD6 Si frames.

All C-dale bikes are made of 6000 series aluminum .

We are also a Trek dealer, and I'd say for the money the 520 is a great little bike. Of course if you have the $$$ for the Rivendell look at those too