I experienced the 747 "business class" on TG970 on Nov. 8th, and I fear I will again on TG971 on Nov. 17th.
By current business class standards, i.e. Thai A350s and B777s, it doesn't cut it anymore - it's comparable to Premium Economy at best.
The seat does not fully recline (and I found it extremely uncomfortable) and there is no direct aisle access ... I don't pay business class fares to sleep poorly and climb over sleeping neighbours.
Thai Airways may consider it adequate as a replacement, more likely their hand has been forced by the B777 incident, but I don't want to risk a substitution like this any time in the future, so its back to SQ for me.