What I think those of you who are thinking of doing a TP run need to calculate what value you would get out of your status (or higher status compared to what you have now) over the course of its validity period, and how much you need to spend, and see if they tally up, or not.

The value may be different for each person/flying patterns, e.g. some of you may only ever fly F, in which case the value of attaining Gold may be substantially less than those who only ever fly Y, unless he/she values the extra Avios earned as a Gold member extremely highly compared to the Y flyer in question.

Bearing in mind even at LHR T5 you can pay to access a lounge (although not a BA lounge), and recouping the costs of a TP run through lounge use may not be easy if you don't fly much, but also perhaps take into account the extra Avios-spending opportunity you can get as a Gold, e.g. Gold Priority Reward at double the Avios at least 30 days before departure, subject to certain fare buckets being available, etc.