I'm trying to make a repaint for the NGX using GIMP. When I open the kit in GIMP, performance slows too a crawl, to the extent that I am unable to get any work done with it. The actual airplane performs reasonably well. Any ideas?

The paint kit is a huge file. It's probably using quite a bit of resources. Generally files with lots of layers put a much higher demand on the system. Got plenty of RAM and a page file running?

Another option is paint.NET with the .psd plugin, both open source freeware and work well.

....and another option is to open up the psd file with Gimp (go and have nice cup of whatever you like to drink while gimp open the file) and then resave the master in xcf format to get rid of about 100 mb file size. Now every time you open up the master we talk seconds not minutes. BrgdsPatrik Soderberg