Tub Surround - Kerdi Board vs Cement Board?

Hello all,

Renovating my bathroom and I am curious if Kerdi Board is worth the money. I have never used it and usually install concrete board. I am not doing anything special here just a standard bath tub and I am planning to install a niche and tile.

I looked up the Kerdi Board Kit which goes for around $500 and claims it comes with everything for a tub surrounding.

Is Kerdi worth spending the extra money on? What is the big benefit? I have been seeing it used all over the place for the past few years.