Hi Andy,
What you say may explain the fact that the Airbuses (all models) glide so much better than the Boeings - the extra wing surface area! I mean with thrust at idle, they really "fly"! This may also explain the successful landing of that Airbus A330 by Air Transat which landed in the Azores back in 2001 by gliding down after the engines shut down due to fuel loss from a defective fuel pump installation-the pilot was a fellow Quebecois from my province in Canada!
I'd love to hear from others though to confirm what you said - especially pilots or engineers.
John