Never tried 507s.
The 507s are just slightly bigger 505s. That's exactly what they look and sound like. Matter of taste as always, there is no right in Hi-Fi. Personally, I've always found Wharfdales disappointing. Loved the old Diamonds though.
Love Skodas. Deceptively great cars and drive as well as their more expensive peers.
My daughter has just bought one of the few low millage Seat Toledos in the world, a rebadged skoda Rapid, and I don't understand why it wasn't more popular. It's a lot of car for not a lot of money. My wife and I have Seat Leon FRs and again, I don't know why you'd buy a Golf? I've had a Golf, good car, but the Leons are just as good and cost a lot less. Basically, you pay a lot for a slightly better cabin in the Golf.