Thanks George, Sketchup is an extremely powerful tool and surprisingly you can be up and running making models very quickly due to it's intuitive slick interface. I have used quite a few CAD tools over the years and I think Sketchup knocks the socks off of all of them with regards to it's sheer ease of use and efficiencey - it is a joy to use unlike some of the clunky overpriced tools I have worked with.
And it's free! Although I have the Pro version, the free version has almost full functionality. I think you should have a stab at it, it really is a breeze. There are countless tutorials to be found on the web and a huge model library which you can download some quite amazing free models directly into Sketchup.
There is a very good news website/forum called 'Sketchucation'. Additional add on tools can also be loaded directly into it - it really is the bees knees.
I've added three more views. One, a closeup and the other two shows off the styles you can present your model in - one is a hand drawn style on graph paper, and the other a monochrome output - this is why it's called Sketchup.
As regards the efficiency of Sketchup, I put together this Cathedral as you see it so far (from scratch) in about 5 hours, I couldn't possibly achieve this with other CAD tools.