I'm pretty happy with what I built. I often think that I should have built it a little bigger....but as it is, everything is within arms reach. Any bigger, and I'd have to get up to reach things that would definitely be too far away. Having worked at this bench for the past three years, I still wouldn't change anything. I have just enough room on either side of my main work surface, that I can keep two kits going, and seperated!
The only addition, since I built the bench, was a paint rack, for the larger Model Master paimts. I hung this on the wall, at arms reach.
All in all, I've got a pretty good situation!