The new SR-L700 is for me not like the other Lambda models, it is comparable and very close! to the SR-009. The SR-507 has harsher highs, a more V shaped frequency response and sounds to my ears a little bit technical. The SR-L700 sounds more natural and balanced, the bass has more structure and all is more cleaner. There are for me no other Lambda modell they can reach the performance of the SR-L700. I prefered the Lambda Nova Signature and the Lambda Signature but the SR-L700 is in a other league and for me one of the best headphones you can buy today.