I've ridden several times now in Thai Airways business class between LAX and KIX. The service is consistently very good -- warm and attentive. On average, I'd say it's better (at least more reliably good) then UA. The only bad thing about TG is their equipment is old. No sleeper seats in Business, no video screens at your seat, etc. Another difference is that TG uses 747s while UA uses 777s, at least to KIX. So that depends on which plane you prefer. I give TG very high marks.