soft or hard vang

[ebb]

Vang is by definition a kind of preventer.
Seen on a cruising Ariel found recently on yachtworld,
the boom is rigged with double soft vangs with bottom blocks on the port and starboard side-corners of the doghouse - the leads aft to the cockpit.

Better with a picture.

But the rig is intriguing. I have been thinking recently whether the Garhauer hard vang is absolutely necessary for a cruising Ariel. It does do away with a topping lift and can harden up the boom in other applications. But it takes a lot of cabin deck away in an important area.

How indispensible is the hard vang for reefing sail in rising wind? Singlehanded.

Anybody have pros and cons on this?