Given this is on our Blog I'll have to keep it brief. I've been multi-day hiking since I was 14 and cut my teeth carrying around 15kg for a weekend out and upto 30kg for a week. When I could afford to get better gear I purchased a huge expedition pack, so I could carry heaps and heaps, and I did.
Something began to change after a float boat expedition into the middle of the central plateau back in 2003 where all those in attendance suffered greatly under very heavy pack weights.
I began to look into lighter gear and things have changed. Now my 3kg pack has been replaced with one around 0.7kg, my 3.5kg 2 man tent with one around 1.6kg, my 1.6kg sleeping bag with one around 0.8kg. You will be getting the idea, without even trying with two up for a weekend I go out now with less than 7kg on my back (thats what you can carry on a flight as hand luggage). Thats with a full first aid kit and safety gear - if the weather is good we might leave the tent fly and rain coats behind and get closer to 5kg two up for a weekend. Its easy to do with light gear and not taking anything you won't use.
I am a convert, light is more comfortable, less taxing, and safer. It enables you to fish on the move all day and I know I cover better water this way.
Come and give it a go.