As of now use of the word investment is more relevant compared to currency. I don't see a reason why for a person needs to exchange to bitcoin on some legit items when the person can just pay in fiat. All those people holding to it are basically waiting for the price to go up. And the word moon says it all

Agree, because bitcoin is limited and the users is grow recently(although it's still need mass adoption), so the price is fluctuating, but not always going up, bitcoin situation is susceptible, if the price is down many people too panic and make a sell wall, so the price down and the whales participate in it.

Also people take a bitcoin as investment too. So bitcoin can be both.

i think bitcoin can do both jobs correctly

It's both right now but hopefully it gets to the point where it's not an investment, just a currency. We want the volatility to go away.

It's hard to say that bitcoin can be used as currency because many governments ban bitcoin utilization in their teritory. It's also bitcoin hasn't ready yet to go mainstream so there's no many merchants accepting bitcoin right now.
In other side many people use bitcoin as their investment or like currency trading. They don't use bitcoin, but they change their bitcoin into FIAT.
In my opinion, bitcoin is both of them. I can use bitcoin as currency only via online trading in some merchants and investment for the future.

I'am going to speak my self only here , I personally see Bitcoin as an investement for now I was too late for the train I guess since I started in late 2014 but I hope I can get on another train so hopefully the price will increase , It can be a currency but for now  .. we should go mainstream and % of world population should start using it before going there .

From my personal experience and my personal point of view, i can say that this Bitcoin for the last 9 months was totally alternative world currency especially on digital world..
But for the day when this bitcoin born and being introduced to public until 9 months ago, i think bitcoin was some very high risk investment thing....

Currency for the nerds, investment for the wise, speculation for the mass

as for me.
bitcoin is a currency and an investment itself.
that is why bitcoin is so unique and hve a great potential.
bitcoin as a currency overcomes usd...
and bitcoin as an investment it is so awesome.
althought it still need to be long term to earn more.
gg..