Thank you all for your detailed feedback, with many good points raised,,. This seems an awkward decision mainly due to the incredible results obtainable from my current kit especially for traveling,,. The D300/D700 with compatible media, battery systems, grip plus usually just three interchangeable lenses have made for a highly versatile relative light weight bag,,. I've always travelled with a backup body and have regarded this as necessity even though I've never had a Nikon camera let me down,,.
1) Good point on the D800 crop factor rendering the D300 reach obsolete,,.
2) I tend to agree with the comment that the D700 wont get used very much, even a the smaller file size could be set on the D800 if that were a need at some point,.
3) An interesting scenario that someone raised is that I could get a D7100 & a D800 and off set the costs with the proceeds of the sale of both of my current cameras,,. This would upgrade my entire kit to state of the art, med. format capable resolution, with effective warrantee's ect,,. Perhaps this would bring back the compatibility I currently enjoy as far as the media and battery systems are concerned? I've never looked at the D7100 and I sure never thought that buying two new cameras would be a consideration prior to poising these questions,,.
Thanks for all who responded and Best regards to all Nikonians,,.