You seem to have an obsession with this disposable-thing. Both warranties work the same way. If the product breaks you send it for repairs. That's it. You get a new product or the old one is repaired. Does not matter if it's Canon or Samyang. It's just that the Samyang offers so much longer warranty it is definately an advantage if you ask me. And where I live neither Samyang nor Canon has a local service center so that's kinda silly argument. It depends where you live.
Superior in what way exactly? IQ is certainly is not the answer here if you ask me. I'm willing to bet 99 % of people are perfectly happy with their Samyang 14mm. It tells us it's a great product with fantastic image quality. Particularly great in astrophotography (it has less CA than then Canon by the way). And so what if it happens to be so cheap? It makes it even more attractive. But so what?
And in my opinion here are all the reviews you need:
Both lenses make fantastic images. That's the main thing. I'm still glad if you are happy with your investment. I know I am with mine. Have a nice day
You send it for repairs? Where? There are NO service centers, in other words, this lens cannot be repaired (maybe somewhere in China...good luck with that!) Cheap can be good. I loved my VW bug prior to becoming auto literate.
How many L lenses have you owned? How many have you sold? Any bias?
My Canon service center is 4 miles away. Probably never need it for this lens. Ever. Oh well....