I have to admit the rules are somewhat disappointing. If the enemy get close to the Portal it is effectively useless as you still have to obey the normal restriction of deploying more than 9" from enemy models. Harlequins should be able to make some use of it as they have a 1CP stratagem to to allow them to deploy more than 1" from enemy models rather than > 9". They also have a 1CP strat that allows the gate to deploy one extra unit if it is destroyed. Unless CWE and DE get those stratagems, it is effectively worthless for us (or at least highly situational).
The only marginal use I can think of is to deploy it slightly forward of your deployment zone and use it to bring a big unit like a Wraithknigth or big unit of Dark Reapers on in your own turn and in your deployment zone to prevent them being alpha'ed if your opponent gets the first turn. 120 points is quite steep for protection against something that is only going to happen 50% of the time anyway. In the case of infantry, you can almost get a Wave Serpent for those points which will provide the same protection and be much more useful during the battle.
I will look to see if CWE and DE get stratagems to use it in CA. Otherwise, I think I will not be getting this after all.
Sanguinius stood up, stretching his wings to their full extent. He flexed his hands. "I need no blade".
It was as though Sanguinius gleamed with pale light, his face white, eyes becoming blood-red, surrounded by the golden crown of flowing hair. Guilliman had witnessed glimpses of of his brother's wrath before, but had never seen the true Blood Angel unleashed. Sanguinius surged forward on alabaster wings, half a meter from the floor, whiteness streaming from him like flames.