A ways back in July, while in Japan, I bought a model of a Gundam, and finally I can show you the build. Kind of apt with the current re-launch of the Tau and all.
Firstly, despite everyone touting GW as the best model builders in the world etc. etc., they've definitely got a thing or two to learn from BanDai, the kit is staggering in its design and complexity.
Take a look at the sprue below. You may notice that the plastic has two tones of grey, that's because they are able to cast the sprue in at least two stages to produce pieces that are already articulated, with extremely complex joints and sliding parts, some actually cast within other parts to move like pistons.
The whole kit is press-fit, I didn't need a drop of glue, and the only time I used any tools was to remove the parts from the sprue, clean the odd mould line (far, far neater casting that GW), and to cut a few pieces of piping to length that were inserted into joints to represent hydraulics.
The kit was essentially two kits in one. The first was the fully articulated skeleton of the model that you can see below. Every joint was articulated with a very wide range of motion. In fact, as I continued to build the model I discovered more and more points of flexure and the number of poses that you could build is mind-blowing.
Once the skeleton is built, you add the armour panels to make up the final model. The different parts are cast in their appropriate colours so you don't even need to paint, and as before, every single piece is press-fit, highly secure, and there are individual pieces for every sub-part of the skeleton so none of the articulation is lost with the build.
The final result is absolutely brilliant, with multiple hands that can be swapped to allow different weapons to be gripped, all sorts of moving parts, and so much possibility.
Best of all, since returning, I've discovered that you can buy them on Amazon and other online retailers, so this guy might just be getting a friend sometime in the future.