Since writing this I've put another hundred or so pellets through both guns, and the TX has settled down to a much healthier 11.4 ftlbs - even Bis Mags & Hobby's stay well under the limit - I'll just have to keep an eye on the power in case it creeps back up.
Unfortunately, the HW hasn't changed at all: still low on power (9.8 - 10.2 ftlbs) and twangy. I've already ordered one of Welsh Willy's fine kits for it.
Consequently, the above scores will have the TX edging it over the HW.