I love it. I miss doing sketches and concept art. I have a huge portfolio of stuff I did years ago. Mainly copying the style that was in the original "guide to vehicles and vessels" book. Loved that book!
Anymore though I find myself just sitting down and making my concepts based on what I already have in plastic, or trying unsuccesfully to scratch build what I want...
I'd love to see some more of this kind of stuff, I especially like the speeder bike, because I think it actually has custom potential....