In general, I use it for both, currency or investment. Because I make profit with bitcoin trading and I also buy sometimes stuff with it, mostly digital stuff. And I save good part of it for the long run.
Nowdays i also started using bitcoin as both currency as well as investement,i started using it as a normal currency.I always earned bitcoin and then spent them straight away but now i have started to do some investement with bitcoins because i have collected decent amount now.I also invested some amount in recent ICO's.