No the GIFs actually make this machine look smaller than it is. As it sits on the table, this thing is just under 6 feet long from left to right, 5 feet deep front to back, and just over 3 feet tall. The chuck is slightly over 6 inches in diameter for scale, the GIF of it facing is a 4 inch thick wall tube.
The steppers are NEMA 24 size. The spindle motors are capable of more power than your power outlet is.

BTW, the boxways and sliding/rotating parts of this machine are huge in comparison to everything in it's size class. I used a Hardinge HLV (very good toolroom lathe) to make some parts of this machine. The HLV has a 6 inch wide dovetail slide on its Z, and something like a 4 inch wide dovetail on the X. My machine has 6x10 and 8x10 boxway plates. Solid, thick slabs of aluminum don't bend by more than a few microns over the distances at play here. The posters on this thread are underestimating the size of this machine and its components because you're used to seeing all the gantry routers on this site that are made from thin walled 80/20 extrusions.

The p5 bearings in the spindles have about 0.0002" runout, the next grade up (p4) has 0.0001" and those are the standard for full sized industrial machines.

On the choice of acetal vs turcite, keep in mind that turcite is not commercially available unless you buy it in big sheets and it costs upward of 10 dollars per square inch. Boxway VMCs generally run for at least 5 years before wear in the boxways is noticeable, most machines aren't rebuilt until at least a decade of running production parts. The hard anodized layer of aluminum is a few thousandths thick and is more abrasion resistant than scraped cast iron. This is not a throwaway machine, it's designed to last a long time and be cheap to maintain if it ever needs to be.


Almost forgot to address this part;
"How does the lathe spindle transition between indexed/simultaneous 5 axis moves and turning speeds? What kind of gearboxes are you using for the rotary axes?"

Right now the C axis (main spindle) uses a worm gear system on a pivot in addition to the timing belt and motor/encoder. The motor pulley is always connected to the spindle and 8192 count encoder gets the position along with index pulses for home. All fast operations, like drilling, turning, threading ect. use the main spindle motor to work. When the worm drive is engaged, the spindle gets a lot more torque and cannot be backdriven, at the cost of speed. This is for milling operations and heavier off-center ops. I suppose it could also be used for tapping with large taps. On the prototype this worm gear is engaged with a small lever, takes about a second to do. The production version will have something similar but with a small, cheap air cylinder and solenoid so it can be automated in addition to hand operable.
The milling head B axis is a larger worm gear with two worms in opposition, they are driven by the same output and can't be disengaged. The production version will have a shot-pin plate on an air cylinder to help with initial alignment and also give a locking mechanism for really heavy cuts and extra rigidity when using longer tool holders that reach further from the B axis centerline.