With all due respect to the Chinese, whilst they can accurately replicate movements, the quality is never as good whether it's a 2824 or a 7750.
The 7750 is particularly vulnerable being a chrono. I would always recommend steering clear of using the chronos regularly. I've never bothered with the chronos on any of my four a7750 watches, two still failed on me.
My advice is buy 7750 watches with a view to replacing with a swiss over time - loads about on ebay, on here etc.
Obviously it is much harder to do this with sec@6 movements so you're kinda stuck. They have improved them over time. If you like the watch enough it's your judgement call how much of a risk it is.