Flew into Japan today and my hotel is half a block from the Yodobashi in Akihabara. Guess what they have in stock? You guess it, 507s. And they had them on display as well at their listening stations. I was swapping between the 202s, 404s, 007s, and the new 507s. The 202s were driven from a 252A amp, the 404s from a SRM-600, and the others from a 006t or 007t as I recall. Source was a Marantz SACD player. At home I've got a 252 with SR-003s and a 006t with 404s. I listened to some classical and some Sonny Rollins. Bottom line? Didn't really hear enough difference, so that money that was burning a hole in my pocket is safely still in my pocket. I didn't think I'd come back with the 507s due to the cost/exchange rate, but once I heard them it sealed the deal. I can wait. The 507s, to me, didn't sound considerably better to my ears than the 404s. Different? A little bit. But different isn't necessarily better or worse. I will say that the construction looks fantastic. They feel a lot sturdier than my 404s and look much better too. I'm sure that those that are getting them will enjoy them, but for me, I'm content with what I have.