Kirk,
Thanks for your quick answer.
Unless there are two buttons, one for a customised Classic and a second for the larger customised IPTC, please do not do away with the ability to switch to Classic. I am a contributor to Getty Images who insist on the use of the Classic tagging of images and that does not include any references to my address, email, website, Facebook, Twitter, personalised IPTC usage or copyright terms etc. All of the who, what, where, when, why goes into the description box. I am sure I am not the only person on this forum that contributes to Getty.
However, when I send images to my website, magazines or private customers my images must have everything embedded in them that cannot be included in the Classic layout. If you do away with the Classic alternative it will be absolutely impossible for me to easily submit images. To do so I would have to use Version 5 for customised IPTC and probably version 4.6.9 for Classic IPTC submissions.
Also, I have experienced problems losing fields during the customisation of the IPTC and I don't think that this has yet been resolved, although I haven't tested the later versions.
I'm using Win 7 64bit.
Here is a recent page of my images so that you can see how they use the IPTC description field
http://www.gettyimages.co.uk/Search/Search.aspx?EventId=166237672&EditorialProduct=Sport