I've got a G1 Zulu (foliage).
It takes some fiddling getting it all adjusted, but indeed they are bombproof. The G2 version has more padding and is more comfortable when carrying heavy loads (I tried one on last year. It can be compressed very small (so you can take it as a carry-on on flights), but can also be loaded way above your shoulder by using the snow collar.
A Zulu really needs a waistbelt, as that's what the whole idea is about: carrying the weight on your hips, rather than on your shoulders.
XTL lids are cool for organising those small little things in your pack if you frequently carry a full Zulu, if not the lid tends to sag. There are plenty of other types of pouches / organziers to put on top of the lid (which unfortunately has no pockets).
I like the fact you can add more pockets and pouches on the exterieur, but take in mind it'll add more weight.
Another thing is to take in mind the import tax, though that's subject to the country you live in.
Kifaru also have their own forums, with a lot of info - all available by using the search function. Also alot of knowlegdeable chaps out there who can answer about any question you have.
On here there are some Kifaru owners, though not much, due to the fact the packs are indeed quite expensive - and the import taxes ...
As for Karrimor: I've had a Sabre 60-100, which I couldn't get along with. It never sat comfy on my back. Later on I moved to a Lowe Alpine Sting, which was a big leap forward. The Zulu is a different game as you wear it on the hip (lumbar), which I'm not quite yet used to.
Also love the slick Express (G2, coyote brown ...).