I am sure you can find a video of any lathe or mill with problems, so it is more helpful to review the information as an aggregate of all the reports both positive and negative.
The Chinese machines you are comparing the 1340GT are not close to the quality of the Taiwanese lathes. It is unlikely as a hobbyist that you will wear out the gearbox or for that matter the ways, etc., these lathes have been around for decades and are still going strong (Grizzly, PM, Eisen, etc.). Main problem is reliability and quality of the components, so failure of a component like the bearings, etc. Warranty, parts and service become a significant factor. The chance of a component failure/quality defects is significantly less with a Taiwanese machine for comparable models. The PM-1440GS does have a 2" bore, I do not see the D1-5 spindle as being a significant cost factor vs. a D1-4, the only cost difference is the back plate which is nominal. Looking at the 8" 4J independent the price difference is $20. We are talking small difference in cost in comparison to major cost for the machines. Comparing the numbers between the machines tells you little of real world function.
I understand the budget and the goal, but when I purchased my 1340GT I ended up doubling my budget, and then you get into the accessories and it goes a bit crazy. But then I am of the philosophy that I buy once and cry once, I have wasted a lot of money through the years scrimping a small amount only to be disappointed and pay more in the long run. Still there is a budget and everyone has to set a limit that they can live with. There is also the 1236GT which is 1K less than the 1340GT. The 1440GS is currently out of stock, but you would need to check to see availability in the near future. The tariffs are also throwing a wrinkle in mix, and cost have gone up and will continue to rise. It all depends on the type of work and size of machine you need, the usual discussion goes buy the biggest machine you can afford, but in many cases a 12-13" swing is more than adequate. It is the person using the machine that makes a the biggest difference, and can do excellent work with any of these machines. I will say that I enjoyed using my 1340GT much more than similar sized Chinese lathes that I have used, but they all got the job done.