New poster here. I've read through the FAQ and some old threads, and can't seem to find the answer I'm looking for. Apologies if I've missed something.

I'm a British citizen living in San Francisco, and I fly back to the UK about 3 times a year, as well as making 3-4 trips within the US (mostly to Boston or New York). I haven't been very smart about miles in the past, but after a couple of very lucky upgrades to BA Club World (both times on a straight economy ticket coming out of LHR), I've started to see the advantage of flying in a better class! Most years I get close to getting a silver card, from taking some WT+ flights, but am usually 100-200 points short. I have started collecting a fair number of miles on my Amex, and currently have about 100,000.

If I wanted to travel in CW more frequently, would it be better simply to build miles and use them for an upgrade (I did this at Xmas and it was heaven) or is it worth trying to get a silver card, in the hope of getting some "free" upgrades (e.g. to CW from a WT+ seat)? Does that really happen? I could get over the hump if I bought a full price CW ticket from LHR to SF, but it is very expensive!