When I looked into Radianz a while back it was primarily to increase speed. After talking with a Radianz person and pressing them on the issue of speed, they stopped pushing speed as an advantage, and pushed reliability as their advantage as well as their multiple partners. Their service is very expensive IMO and they admitted it wouldn't be worth doing unless you had 3+ Radianz partners that you wished to connect with. If you can do a direct line you will get more speed and it may be cheaper than going with Radianz though from the UK to the US a direct line might be a totally different ballgame pricewise.