Hi kwik.stix,
We are evaluating adding a few more UK locations but also adding more servers to the pool for the London location. We've actually done just that a few times over the last few months and will most likely continue with that in the near future.
Also, connection speeds can depend on what the user is doing. We've found that the connection speed drop is relatively minimal when a user is downloading a single file, but when multiple files are downloaded the speed does noticeably drop.
We are also working on other techniques/optimizations on the network to improve the connection/download speeds.
Hope this helps,
Davidek