So basically, arcanists start out very narrow on one end, get much bigger in the middle, and taper off on the other end. (IYKYK)
OK, on a more serious note: so after testing Arcanist using my less-than-refined skillset and reading the observations from people who appear to have a lot more skill with the general game than I do, I have come up with a theory of how the Arcanist works in game, and why my experience with it has been so much better than the higher tier players. I represent this in a drawing, to make it look all official-like, which I present here:
Summary: Arcanist is currently tuned to boost the effectiveness of mid-tier players like me, at least as far as soloing content is concerned. However, it's core mechanics apparently deviate from regular gameplay enough to work against experienced players, or is tuned specifically for middle of the road players like me at the
expense of the top tier.
That's the only way I can explain my experiences testing, compared to the general feeling that it's lacking based on other player reports. Basically, I've been going through Craglorn and a few other zones using equipment I already have in-game (with the notable exception that on PTS all that equipment is usually gold, whereas there's a lot more purple live, but I did do a few runs with all purple, craftable-exclusive gear as well) and I've been soloing encounters that have traditionally given me trouble. And what I've found is that for me, arcanist performs significantly better (even without my favorite crutch, the ring of the pale order) than any other class I've played (I've played everything but warden, for some reason I just can't get into wardens). And what I find is that the rotation is straightforward enough that I can keep track of it and because of that I'm able to be a little more situationally aware of what's going on, and that plus the Emerald Spotlight of Infinite Aggression makes it possible to hold my own in a lot more situations than I would normally be able to manage. And if you add a ring of the pale order into the mix the odds increase even more dramatically.
I haven't tested group play as much, so I can't extend my theory beyond soloing content.