With respect to the "harsh ride" thing - I have found that I like a touring bike to be a bit stiffer than one which isn't to be used for fully loaded riding, since the extra load makes "normal" bikes flex and wobble too much. So something like the Cannondale (or my Co-Motion Americano) might feel a bit stiffer than usual when ridden unloaded, but put a load on it and it's in its natural environment. It settles down and becomes a very stable, pleasant ride, one that doesn't shimmy and wobble all over the place the minute you try to stand on the pedals going up a hill. So it's important to consider what you want to use the bike for - if it's going to be used primarily as a fully loaded tourer, then test ride it with a full load. The Cannondales have stirling reputations as touring bikes - I wouldn't worry about the aluminum aspect at all if I were you. If, on the other hand, you want an "everything" bike that can be used both for around town unladen or on a fully loaded tour, then you will inevitably be making some compromises, since you want the frame somewhere in between in terms of stiffness. Buy the bike for the application - no one bike can "do it all".
Other things to be aware of when looking at a touring bike (just my opinion):
http://www.crazyguyonabike.com/doc/page/?page_id=148087
Neil