The OCR touring is an interesting bike. It rides very well loaded, and just a little on the harsh side unloaded. The OEM tires are junk, get rid of them immediately. Old Man Mountain makes a front rack that works just fine, and almost any rear rack will work, however you will need to add a spacer by the brake caliper which puts your rack just slightly off line.
The 105 long cage derailleur will handle a 32 tooth rear cassette, which I found was all the gearing adjustment I needed. I believe that the 2005 model had more suitable touring gearing.
The Avid disc brakes are awesome. It does take a little time to learn to adjust the pads, but it's not hard.
The adjustable stem creaks. You may wish to buy a threaded non adjustable stem after you have dialed in your position on the bike.
This bike has been discontinued by Giant, and you would only find a leftover model or a used bike.
I replaced mine with a steel cyclocross bike, which was more adaptable to my riding style.
Jay