A new machine will not not have the wear that will be present in a machine that is 70, 80 or more years old.
I started with a used Myford ML7, but despite spending money and time on it, it did not always do what I wanted, so it was replaced by a new, larger, Chinese lathe. I have been happy with it for 20 years, but have never used it to its full capacity, nor never will, probably.
Smallest item, 10 BA bolts; largest cast iron just over 6" diameter. Threads 4 mm pitch down to tapping 5 x 0.5 mm
NOT portable, at 300 Kg.
Don't use my mini lathe that much, but have yet to break anything. Powered through a surge protected mains lead!..
There are now many mini lathes being used by model engineers, without problems. Properly treated they do what the owners require. Most are sold as "Only for Hobby Use"
Some very good work be done o Chinese machines. (I have seen at least bone wrecked by ignorant abuse! )
A 400 watt motor and the gears to match it are not meant for taking 1/4" deep cuts in steel, any more than a 850 cc Mini was never intended to pull a 15 ton load…
If you want Industrial durability, you pay for it, AND HOW compared to hobby machines.
A SC2 or 3 is portable, just, by one man at about 35 Kgs.
A SC4 is not at about 125 Kgs.
As always, the advice on "What lathe should I buy?" has to to be "Think carefully about what you want it to do", subject to space and budget available. And perhaps, "What are your capabilities?"
What is produced is very much dependent on the operator. Any fool can produce rubbish on an excellent machine. Making good work on a worn machine requires skill and knowledge, but it can be done.
(Very probably, not by me! )
Howard.