Well, the Arcane arrived and I installed them this afternoon. I recorded my original Aguilar 4P60s and these new Arcanes dry and direct, same bass, straight into the interface, playing the same line so I could compare by jumping back and forth between tracks. Strings are a relatively new set of Pyramid flats.
At first I matched the height to where I had the Aguilars and the Arcanes seemed a bit lifeless. Slightly worried, I dialed them a little closer to the strings based on the "standard" heights recommended by Fender which definitely helped and this got the waveforms in Logic looking pretty similar in amplitude between both sets. Subtly balanced the strings and was good to go.
Very subtle differences here, but I'd say to my ears, the Aguilars are slightly warmer/thicker in the low mids, with slightly more low end. The Arcanes seem more linear through the lows and mids - which I guess sounds a little more clear - a bit less thick but still nicely balanced, and maybe ever so slightly more texture / glass / wood whatever you want to call it in the top end. All in all they sound quite similar, and both sound great, definitely down to a matter of taste. Playing live, and in a mix may unveil some different nuances of these Arcanes as well. I'm interested to see how the cleaner lows and low mids may translate to more clarity in a live setting. Overall, really liking them so far and will not be going back to the Aguilars for the time being.
Also want to note that pickup height is an impossible variable to deal with in a comparison like this, as they required different heights which means subjectively dialing it in until it seemed similar enough in output/tone. The tonal differences being evaluated are so subtle that you can never fully rule out the influence differing heights may have on outcome.