Hi there!
On the face of it there are not that many extra benefits with a Gold Card and to some perhaps less after the removal of the open access lounge policy.
Upgrades - cannot remember the last time I got one of those but these days usually in F or CE so not that relevant. When I used to travel CW a lot I got one J to F in about 5 years.
When the card comes into use is when things go wrong. This can be all sorts of things but BA will just generally be much more accommodating and helpful, or that is the difference that I have noted over the years.
It may be my CV score that is helping as well but in general I get the impression that they do help Gold's more than Silver.
FD.