Thinking of making the 640 my first smart phone, ever.

Hey guys, as said in the title, I'm thinking of making the Lumia 640 my first smart phone ever. I've never really been into phones, I have always used cheap, outdated ones on pay as you go, but, after years of weighing up the pro's and con's of a smart phone, I think I am finally ready to take the leap of faith.

Does anyone have or has anyone here had any experience with the 640? I think I'm going to get the phone from the Microsoft website and get a SIM only deal from EE. (I'm in the UK)

Also, does the 640 have the 'Hey Cortana' feature? Or do I have to wait for windows 10 for that?

Thanks!