froob: Probably the best advice is go with what your friends / family have.
I have an Xbox One, mainly because I've had an xbox since the original. The original xbox was way ahead of the PS2 in terms of network multiplayer games. But, the consoles seem to be more and more similar with each generation.
These days I pretty much only play Destiny from Bungie, so could really have gone with either option...
Well, none of my friends have consoles and my family live in Los Angeles, Toronto, London and Manchester...! So I won't be popping round to share games any time soon. One of my brothers has an X Box 360 I think (the youngest one) and another had an original X Box but his wife probably long ago talked him out of that...
I don't know how much speed you need to play on line reasonably but as you can see we do not have a lot here and may end up with less if we move to Queenstown as we hope to do.