Think I'm probably finally about done this league. Not a ton left to do really besides farm for voices at and make a herald build, which sounds entirely uninteresting.
Archmage brands is the best thing you can do this league, probably even better than herald stacking if you account for just raw map clear potential. Heralds might have an edge in pure simulacrum farm, but that'd be about it. 100% going to get nerfed, so discounting that some random thoughts of the like 10 builds I fucked with:
Warcry builds are ridiculous. You can use basically any skill you want to backed up by 4-6 warcry medium jewels and just do omega dps. It's so good I suspect it will eat a nerf along with archmage. Played various versions of it with bladestorm, reave, glacial hammer, and they all hit 10m+ shaper DPS with ease. Bladestorm particularly gets hilarious with a +1 storms enchant cause it starts instantly phasing bosses with them all stacked up.
Toxic rain/caustic arrow was the best league start I've ever run with. Easy story, progression in to maps was smooth on basically 0 gear. Sucks dick for bossing though, especially sirus who never stands still long enough for toxic pods to do their thing. Very good option for next league though if you want to just build early currency. Caustic arrow with arrow nova support was one button screen clears all the way up in to red maps on SSF rare gear.
Bleed bow gladiator was probably the most fun I had this league. Split arrow bleed explosion clear is super strong, and it's all just fire and forget since you're not using crimson dance. Giant single bleeds just take care of everything. Assailum hat with snipe does some pretty dumb shit with puncture in it and a full charge slaps out like 50m damage in a single bleed, which is quite funny on bosses. Not super practical vs Sirus, as if you miss your initial shot as he goes in to phase 3 it can be very hard to hit him again with it. Crafting the bow for it now is kind of annoying after the fossil nerf, so maybe not ideal as a league start.
Block gladiator is still easily the safest and best bossing character. The clear speed is "fine" but nowhere near on the level of something like brands/bows obviously. Absolute free roll for shaper/elder/guardians/sirus though. Only thing that could maybe rival this for bossing would be like agony crawler jugg, but that build is cancer. If you want to just play one character for a long time and scale in to endgame bossing this is probably the choice. It can operate on SSF crap gear, but also has a very high ceiling to scale damage.
Stone golem elementalist was surprisingly strong, and amazingly tanky. You can get up to like ~1800 life regen between golem buffs and life recovery available from items, along with like 30k+ armor, plus you just run around like an idiot mostly while golems do all the work. Minion AI was better than I was expecting having never played minions before, but still annoying sometimes. The minion recall spell helps a lot, but the cooldown was just slightly longer than I wanted it to be. I doubt I'd league start this though given the reliance on the primordial jewels, as they are likely hideously expensive for the first couple of weeks.