The only real benefits of text-derived subs are that: 1) they can look better, 2) they can be easily modified and corrected, and 3) they can be used with old-school MKV players that don't support BD-SUP files. That's a short list of nice-to-haves, but none of them are critical.

So if there's even a chance of the odd OCR mistake, I'd rather stick with the graphical subs, because they are actually still pretty decent, after all. That's why Thai OCR is the only one I'm willing to go for, even if the Chinese OCR looks okay to me.