Well, Stig is doing the UI for himself on the first place so i dont really think something will be done about the hpbar positioning although if we collect lots of similar replies he may be bothered about making an additional UI version(cant promise anything thou).
One of the main reasons this UI is great is due to the positioning of among other objects the Health Points bar.
Nothing more annoying than having vital information hidden along the borders of your screen, you should be able to check everything quickly with the blink of an eye while not losing sight of your focused target/area. This UI helps with that - usability is top notch.
The Stig did a wonderful job, that he like Skyrim's awful graphical style is really only a minor thing, for all I personally care he could color the UI orange, it doesn't even factor into the main reasons why this UI is 100 times better than the normal UI.