Considering your requirements:
1. Home shop/hobby lathe
2. Around/under $1500
3. Small enough that a guy and a buddy or two could move, large enough capacity to be useful for potentially light industrial work
Here's my 2 cents.
Traditional cast iron frame. This keeps the cost down, is well proven and is a good damper of vibration.
Hydrodynamic ways. Again, this helps meet the cost goal and is more than adequate speed wise for the home shop. Also, hydrodynamic ways are better vibration dampeners than roller type ways.
A decent size through hole in the spindle. this is a limitation mainly due to size, but put the bigest one you can for the chuck size. This drives in cost for bearings, and larger spindle blanks, which is why you don't see it.
Cam lock spindle, so you can run it in reverse if you need to.
Variable speed reversible drive, with easy range changes. Speed range that goes slow enough for a 50 SFM speed at the largest diameter that can be turned, high enough for 400 SFM at smaller diameters.
Ample power for the size of the lathe.
Gap Bed
T slotted cross slide that can be used for boring, or mounting a tool on the back side.
Turret tailstock. Step drilling is a tedious afair, and this would certainly help that out.
Electronic Leadscrew. This would be used for threading and tapers. It would mimic manual operation for turning and facing. This eleminates the change gears/quick change gearbox and much of the mechanical gearing in the apron and replaces it with electric motors controlled by an electronic control box and manual switches. This would keep the handwheels for complete manual operation and use the motors for power feed manual operations. The acme lead screws could still be used to keep the cost down, since only using it for threading and tapers would not require backlash compensation, since all the cuts could be programed from the same direction.
As for size, build it as big as the $1500 budget would allow. I suspect that the cost of the electronics and motors for the leadscrew would be largely offset by the mechanical components that they replace. The headstock, drive, and tailstock would increase the price, so this is probably in the 8" to 10" swing by 24 or so between centers range. I am assuming built in China under close US supervision for quality control.