Is DFHack Autolabor a decent alternative?
Depends. If you are really diligent about removing shops you don't want used, autolabor works pretty well. If you, like me, leave mason shops littering pretty much everywhere you mine, that silly manager will split work orders up and almost always send them to the absolute worst workshop, even if you really wanted it all sent to one or maybe two workshops.
My midgame is usually just Manipulator and the basic game's interface. If the check-marks applied to assigning labors, and not just nicknames, I don't think I'd have any real complaints.
I tend to have a dedicated area with 2 of each workshop type after the first few seasons. I'll have to give it a go. Is the performance boost significant with 64 bit?
Might work fine.
I'd mention that for me, anyway, it ends up with a lot of "jack of all trades, master of none". I don't know how the priority system works. I'm confident I could make it work better if I understood it. I think a lot of the "problems" I'm seeing are caused by the flurry of small-quantity work orders the manager spawns every day, which are not in the same sequence that the dwarves became idle.
It's not the oldest labor, but neither is it necessarily the best match for the newly-idle dwarf. If the newly-idle guy is a master carpenter, he might be assigned to be a cook or whatever autolabor thinks is the highest priority at the moment, and the master cook, who had been assigned to make rock mugs because the craftdwarves had all been hauling wood, might be sent to the carpenter's shop as soon as he's done.
I find autolabor is actually best suited to the early- to mid-game when it's important to minimize idling, and manipulator/therapist best for later when you prefer to be choosing the level of quality you are producing.