Only Chinese manufactured tire that I know of that meets same stringent ISO audits (TS 16949) that my company has to meet to compete in the world market and have a good reputation when it comes to manufacturing a Quality product....To attain this certification, they have to prove out and have records on all manufacturing and Quality processes involved in their manufacturing processes. All training records, management, finances, ESH, HR and on...So I too will look at these tires when time to replace my GY G614's due to the fact that they cost less but seem to be every bit as good as the GY G614's.
Yes, GY will repair/replace tire(s) or repair any damamge done if one of their G614's fail...Don't know if Sailun will or not...haven't heard of any failures from them yet, so guess the jury is still out on that...would be best if there never was a tire failure and one had to replace a failed tire or repair damage to their 5er caused by a failed tire.
I'd recommend the Sailuns to the OP and tell you I think you have a good one...keep us posted if you don't mind on how well they do. Keep inflated to recommended psi...
thanks,
Jim