There is more than one way to answer this question. Firstly, we are not seeking to be distinctive. We are seeking to be a living testimony of our Lord and His witnesses through whom He can move. We have an extremely rich heritage from the people of God who have gone before us but we do not want to simply keep a tradition. We are seeking to go on further with the Lord. We have not arrived at the goal but we are pursuing to gain Christ and fulfill His desire. We believe the Lord is leading us and we are trying to follow Him.
Truth never changes but our understanding of it should grow and become more clear. This is to "arrive at the oneness of the faith and of the full knowledge of the Son of God, (Eph. 4:13). Concerning practices, every Christian has his preferences according to his tastes or how he experienced the Lord in the past. We are not for particular practices. How we sing, pray, read the Bible, meet, etc. is not the main point. The main point is to come to the Lord, opening our whole being to Him, so that He could enlighten, strengthen and fill us with Himself. If a practice helps more of the saints touch the Lord in spirit than the way we are practicing, then we will gladly change.
So, the most distinctive characteristic of the church in London is that we are pursuing the Lord.