ISP is Virgin Media "up to 8mbps" over BT landline - which is the real limiter - Airport from Netgear.....
Best of three tests using Speakeasy was Seattle at 1936 download, Washington upload at 375; using
Speedtest.net:: Maidenhead (near London) 1524 download, 379 upload; Napier, New Zealand 1255 download, 332 upload; Seattle 1593 download, 369 upload.
I guess different organisations use slightly different criteria and set-ups for their tests, but it's curious the best results I got on both were through Seattle. All tests run at about 17.20-17.30 UK time.