Well, looking at many reviews with a lot of pictures, I'd say D900 gives better photos than the N73, though the interface blows...
Also, as for importing messages, I was excited and checked the link. Apparently, you can only export the messages from your old phone to your PC using the PC Suite, something which I have already known a while ago. It is pretty simple, really. Use the Nokia Phone Browser, go to message, highlight the messages, right-click 'em, and click on import somewhere. This imports as some Excel file though and you cannot import to your N73 using this method.