Looks pretty good to me

. I would just have zoomed in on the plane a bit more...
As for the compression, you'll find that the lighter the picture, the bigger the file size (in general). As you have lightened this picture, it made the file size quite large. I don't know that you could have fixed this much...I find that generally my edits are more compressed then my raw shots as well. Experiment all you can with photoshop and Irfanview etc. to see how much you can get...but in the end sometimes you can't do much :-/. If you want to show us the full uncompressed picture upload it to somewhere like screenshotart.com where they allow pretty much unlimited file size...
- Kevin
