This really isn't a fair like-for-like comparison at present, since this Region 4 release is essentially a bare-bones rental disc only. The Region 1 version is available as a two-disc set with a pile of extras and a dts soundtrack which will hopefully find their way to the Region 4 retail version when it is released here in a few months.
The Region 1 disc misses out on;
The Region 2 disc misses out on;
The Region 4 disc is certainly a bare-bones rental effort and at this stage the Region 1 or Region 2 (UK) is the version of choice. Incidentally the UK Region 2 disc is dual coded for regions 2 and 4, so hopefully that is a fair pointer to the version we will be receiving.