Well given it is only available in 32gb in most markets and does not fully support internal memory integration I would say it is a step back. I would rather buy a 128gb S6 edge or 64gb edge plus.
My 64gb Edge plus is currently my main driver because my 32gb Z5 premium with 200gb sd card does not cut it given the sd card limitations pre marshmallow.
Actually, I think Samsung made the right decision not use Adoptable Storage.
I would rather be able to pop my SD card in and out without wiping it all and not being able to use it on any other devices.