Interesting question. I've been BA Gold for a while now, and am on my way this year to making AA EXP as well. Having a continental European address and doing at least one DONEx or AONEx a year, retaining BA Gold is easy. I've decided to add AA as the miles I earn there have higher value than the BA miles. So in my case, it's an issue of redeemable miles rather than pure status. But the other benefits of EXP are nice too, specifically the eVIPs.

I still use my stash of BA miles for the occasion MFU booking, but since I'm trying to avoid LHR as much as I can, the benefit of BA Gold is diminishing for me. Still, I'll definitely renew it as it's relatively easy to get.

I've looked at CX as well and I would probably switch from BA if I were to live in or near HKG. The (sometimes unofficial) benefits of CX Diamond are attractive only if you fly CX a lot, and I've had several op-ups on CX as a BA Gold. I've never considered QF Platinum as I've been spooked by the redemption horror stories, and it's harder to attain than BA Gold. I might consider it if I were to live in Australia or nearby.