Hi guys - this is WIP. I'll post it properly once it's updated.
"Which case should I buy" is a weekly question on the forums. Many of us use the KR system, but it can be quite complicated at first, and their website isn't great at explaining it. I thought I'd put together this guide to how I use the system to help anyone considering it.
Types of case
KR does a number of different cases, including small cases for dice, soft sleeves for Blood Bowl teams, etc. For carrying armies, we'll concentrate on the three main ranges - the Card Multicase, the Kaiser bag, and the Aluminium case.
These cases come in different sizes - the standard being the size 1, holding ~100mm of foam trays. As size 1 case is good for a normal, 1500-1750ish point 40k army (depending on how many models/vehicles etc). Most of my smaller armies fit in one size 1 KR case. My larger armies fit in two (usually one for infantry and one for vehicles). Apocalyse armies might take three or even four.
Card Multicase - This is a tough hard cardboard case with a carry handle. It's available in standard size 1 and 1/2 size. They are surprisingly durable, and very cheap. Many people just use these on their own. They also make very good storage boxes on the shelf.
Kaiser bag/backpack - These are fabric carry bags with stiffened sides and pouches for your books. They do not hold foam directly, but hold the card Multicases. So, a Kaiser 1 can fit 1 standard size 1 Card Multicase, a Kaiser 2 fits 2 Multicases (or four 1/2 size Multicases), etc. They are also available as backpacks, which can carry 1 or 2 standard cases
Aluminium Case - These are hard sided aluminium cases - the sort DJs use for CDs. An Aluminium case, like the card cases, carry the foam trays. (You can't put an aluminium case inside a Kaiser bag!) So, a standard size 1 Aluminium case holds 100mm of foam, and a size 2 holds 200mm of foam, and so on all the way up to a size 4...
How I do it
I prefer the Card and Kaiser system to the Aluminium cases, since it's very modular. All my armies are in card cases on the shelf. I own a Kaiser 2 and a Backpack 2. When I'm going to a game, I just pull the card boxes off the shelf and into my bag, and go. No tray-swapping is required.