If you want to travel light and keep the feel of the bike the Giant Loop Luggage system is a great choice. They make the bags in a couple sizes, To fit anywhere from dirt bikes to large bikes like the GS etc. My Giant Loop is the first generation bag and several updates have been made since my purchase (larger zippers, waterproof material, no bolting, etc).
I've ridden with the GL on a couple long desert trips now and it's worked flawless. I love how the bag keeps everything tight to the bike, nothing moved or shifted during the entire trip. It's amazing what you can stuff into the bag once you start packing. I also like that there is no framework to break/bend in a crash. I keep my sleeping bag/pad in a separate dry bad strapped on top of the GL with the built in straps.
For light weight fast travel the GL is the way to go!
Here's my setup for traveling on my 530EXC. Mostly composed of ultra light weight back packing gear. Stored in a Giant Loop saddlebag and a regular dry bag. Some of the major items are:
*Big Agnes Lost Ranger sleeping bag & Big Agnes Sleeping Pad
*Reactor sleeping bag liner
*Collapsible water bottle - boil water, fill bag, wrap in jacket liner and place in bag bottom of sleeping bag for really cold nights.
*Collapsible water bucket (not a must have but nice to keep around the fire in case of emergency)
*MSR Wisperlight International Stove & Fuel bottle - (Since switched over to a Jetboil)
*Bug head net
*Camp Chair - I used the A-lite 2 Leg chair and loved it - CLICK HERE FOR A VIDEO REVIEW OF THE CHAIR
*Big Agnes Seedhouse 2SL Tent
*Misc pots, utensils, first aid kit, camera batteries, light ect.
Did a 1100 mile trip with the original Giant Loop a couple years ago and a 1500 mile trip through NV last summer, worked flawless. There were 6 of us on the trip and 5 out of 6 used the Giant Loop, everyone was very impressed.