The slow down isn't usually the result of your VPN provider. The cause is usually that your router doesn't have the processing power to quickly handle the encryption functions. My speeds from STX to Miami are great using StrongVPN (ReliableHosting). I do have a powerful router with a attached processor to handle all the VPN encryption. My speed reduction is less than 2% when I compare using the VPN between St Croix and Miami or run a speed test not using the VPN on the same route.
I have no problems streaming Amazon or the BBC from London.
USING VPN
http://www.speedtest.net/my-result/2815691577
NO VPN - ST CROIX - MIAMI
http://www.speedtest.net/my-result/2815705651