I had the choice of booking BA/Qantas WTP or Thai Economy from New Zealand
to UK return. WTP seat pitch appears to be 38 inches, against 34 in Thai
Economy [and 31 in BA/Qantas Economy]. The fare is about half way between
Thai Economy and Thai Business. [The UK taxes are much higher on WTP, which
they regard as Business Class for tax purposes.] I would have chosen Thai
anyway, but what confirmed me in my chose was that as a Thai Frequent Flier
I can carry 30 kg in Thai Economy, but am allowed only 20 kg in WTP.