@xzswq21
Let me reveal the machine in my workshop: a quantum D250x550, 20+ years old. Like this one, but bench mounted (~135 kg):
https://www.wgm-maschinen.de/metallbearbeitung/drehmaschinen/quantum-drehmaschine-d-250-x-550-vario.html#&gid=1&pid=1Quantum and Optimum were the two brands Stuermer had back then. Quantum for lower cost, Optimum for full features.
The equivalent machine today would be the OPTIturn TU 2506.
It's a China machine, but has served me well. The bed ways are straight, ground and hardened. Achieving 0.01 mm tolerances is no problem, I've used it for <0.005 mm as well, but this requires some care.
Are there downsides: yes of course. The rear chip guard was a pain in the a** and got thrown away. Changing spindle speed means relocating the V-belt (the new vario drives have solved this). Changing feed or setting up for thread cutting means playing around with gear wheels. The cross slide is too narrow and has no T-slots for accesories.
I've used the machine for aluminium, brass, steel, stainless steel, alloyed steel with no problems at all. It's not a machine for making big chips, but it's precise.
In short: don't be afraid of Chinese machines from a reputable supplier.
Go for the TU 2004 or TU 2304 (preferred) or similar, then this saga is over.