I've bounced between Bronze and Silver for much of the last 10 years, but made Gold last year for the first time. My opinion:
- As others have said, the really big/useful jump up in benefits is getting lounge access when you make Silver. But....
- The lounge provision (especially at LHR) is quite a bit better if you are Gold - so if you spend lots of time hanging around LHR, Gold will improve your experience considerably.
- Ditto the First Wing at LHR - a significant upgrade!
- The 'soft landing' to Silver is going to be a big benefit for me - I am flying much less this year than last, so when I hit gold late last year, it was good to know that I had at least Silver guaranteed until early 2020.
- The big difference I've noticed is in general 'sucking up to you' benefits. The contact I have with BA is noticeably more, shall we say, 'accommodating'. When I call the Gold line, the phone gets picked up straight away - and you generally get somebody who knows what they are doing. I have never had to HUACA in order to get something done. I generally get a CSD welcome when on board, the Golden Ticket is a great initiative, and so on.
- Additional reward availability for Golds is a huge and very underrated benefit. Decide in June that you want to get 4 people to Mallorca in August - no problem (and if used in that way, can save hundreds compared to buying flights).
For me, Gold has been a very good experience, that I'll be sad to lose at the end of this year. I would definitely change my flying behaviour to the tune of 200-300 extra TPs to qualify again (i.e. if I was going to hit around 1200-1300, it'd be worth me TP running for the rest) - but not for the more like 800 extra TPs I actually need to do!