@jelanier maybe you could just say what you’re looking for?
Are you looking for a machine with a huge work area that’s also suitable for milling PCBs?
Put simply, Carbide 3D doesn’t have one. The Shapeoko can do it but that’s not really its thing. It’s a router, it cuts shapes out of stuff. You need to look for a screw-driven machine like this one but to get one that’s as “batteries included” as Carbide 3D’s machines is going to cost you a fair bit.
That said, some folks on the forum have had luck putting ballscrews on the Shapeoko, with which you can get the oodles of precision you’re after. 1604 ballscrews + stepper + 8x microstepping = ~0.0025mm positioning.
“But microstepping isn’t accurate” you might say and on a mill hogging metal I’d agree with you but milling PCBs doesnt involve a whole lot of cutting force so I don’t think it’s a major concern here.