What are the differences between Specialized Targa and Henge?
So, today I got both saddles, and I can answer my own question :-)

Those saddles are twins, you know already about the weight difference (Targa is heavier), and the only difference I found which was not in spec is flex of the shell. Henge is very stiff (the shell, not the padding), while Targa is rather flexible.

And while I am writing this, I rode Henge Test 143, it is very comfy for male organs (three of them), however because its wings don't flex down, it constantly gets in the way of moving thighs. 130 version might be the better though in this regard.