Although I have not gone through the program, I have a word of advice. Be certain that you want to practice in England for a long time. Once you practice over seas, it is difficult to come back to the states. In other words, you get stuck out there.
The reasons for this is that the law is different. So when you come back you have to re-learn US law. Luckily, UK law will be similar in several areas of law. Another reason is that no one will want to pay you the same amount as a third or fourth year associate when you have never even practiced a single year in the US. If you are beyond your fourth year, many firms will not hire you because, generally, you cannot bring your book of business over.