The ARX count is a new thing and I've hit the 400ARX cap each week (apart from that first day) so far, so it hasn't affected how I play or how much I play, but possibly because of the cap.
Generally speaking I'm target focused, and hitting the cap each week (usually by the end of a Friday session) is just another box to tick, which I like.
I think if I were getting towards the end of a week & had not yet hit the cap I might do a few actions to reach it, but more to tick the box than any real desire to be saving up for anything, and I think that's probably more related to it being a new feature and my not having a large stock of ARX yet.
It certainly doesn't make me want to play less, and my daily to-do list is always so full I have to prioritise anyway if I don't want to spend half the day playing
Bugs aside I only see positives in this, I've bought one skin with my earned ARX so far and have enough for another but there isn't really anything I want (that I can currently afford). No intention of buying an ARX pack, I think it would undermine the sense of having 'earned' a skin for me.