Oops! It seems that I asked a question about upgrading gear in the wrong place and it was moved to here. My mistake.
The question was meant to be about equipment for terrestrial photography not Astrophotography but I forgot to mention that. Perhaps I should really be asking it in a dedicated photography forum and not one whose main focus is astronomy.
But thanks to Speech and Multiweb for the replies.
I often use Simon's approach, but I suspect that, like Marc, I really don't have a pressing need to upgrade. The tricky part of decisions about new camera gear is that they are often packed with 'new' features that I'll never use, and the improvements in the areas that I could use are often pretty small in reality.
I should probably take a rain check on the chance of a new camera and keep working on the skills for a while longer.....
Cheers,
Chris