I got my Zulu pre-owned at a fairly bargain price, although it was hard to tell that it wasn't new. It's a G1. The G2's have an improved back system, and it does look genuinely improved, not just changed to sell more sacks like some manufacturers do.
My G1 Zulu is by far the most comfortable sack I have ever owned. On one trip into the back of beyond I had it loaded to the absolute maximum. I don't have lightweight gear, either. As well as camping kit and provisions (at a 'luxury' level) for four days, I had climbing, rappelling, caving and SRT gear and a selection of knives (of course). I even took a fold-up seat! I had a large ATS GP utility pouch on the back, Kifaru long pockets on either side and two ATS medium GP utility pouches on the hip belt.
I have no idea what it weighed, but it was a lot. Below are a few pictures of the setup for a later trip, but not loaded up nearly as much. Imagine the top extended up by another eight inches or so, with a rope bag strapped atop.
Since I had just got the Zulu, I tried packing both it and my Berghaus Vulcan with my kit. The Vulcan (100 litre+) took the load more easily, as it should, but the difference in comfort between the Vulcan and the Kifaru was like night and day even with the Zulu vastly overloaded. I had carried the Vulcan around Scotland for hundreds of miles (and the Pennine way twice - that's a 250 mile hill walk in the UK) and always appreciated how good it was but the Zulu blew it away.
I'm saying all this because I would really recommend Kifaru kit if you can afford it.