I just want to chip in my two cents on this.
Back when I was making ROR tracks in Sketchup, I swore blind I would never use Blender because it seemed so complicated. I said "Sketchup is easy, Blender hurts my head" - and now, it's completely the other way around. I've been using Blender several months now for other projects, and every now and then I go into Sketchup for the lulz and it's impossible to work with in comparison.
The controls and tools in Sketchup are hard to deal with and ultimately hold you back, but the main issue is performance. The problem is that Sketchup cannot join edges. Think about a cube, just a normal cube, six faces. You'd expect those faces to be joined up at the edges, making one solid object that's only four verts, one on each corner, right? This would happen in Blender, but Sketchup doesn't do that, so each face is separate. Each face of the cube is four verts. Think about it - 6 x 4 = 24. 24 verts for a cube. One cube built in Sketchup would take up the rendering power of six cubes built in Blender. Of course, cubes aren't much, but think about that multiplication on a track and a stadium. Bottom line is, even the simplest models in Sketchup are stuffed with far more verts than they need to have. No matter how conservative on verts you are with your Sketchup models, it will never perform as well as if the same model with the same wireframe was built in Blender.
Like I said, I used to be devoted to Sketchup and swore I'd never go to Blender. I thought it was big and scary and complicated, but it just needed getting used to. Once you are up to speed in Blender, you will never look back. Everything is easier to operate, the tools are better, you have more control over every single aspect, and as a result it's quicker. And it doesn't mean you have to abandon your Sketchup projects and start over either, because you can easily import the model into Blender, fix it up and continue from there.
I'm telling you - you will be better with Blender, and in the long run it's a hell of a lot easier.