I really like your introduction to modeling, Jonathan, and your explanation of the modifiers. Very useful. However, I agree with another poster on here that this is way too complex for an unassisted modeling task. While I am not new to Blender, I am new to modeling objects that rely on array modifiers. I find that the introduction to modeling in the fundamentals and the introduction to mesh modifiers preceding this exercise is definitely insufficient to make new users comfortable with completing this task. Namely, because there has not been any actual modeling tutorials at all in the preceding material with the exception of the chain (which did not explain how to create the initial link). A step-by-step tutorial on creating the column (rather than a walk-through) would have been a nice addition to this section.
New users generally cannot propel themselves into full-on, unassisted modeling of such a complex object without first being shown how. If it wasn't for an ancient tutorial by Andrew Price (Blender Guru) on the subject of modeling a wheel that I had completed years ago, I would be completely lost as to where to start. Even so, I feel rather lost because I've forgotten most of the technique (which is quite particular for a wheel). On the other hand, if this was a exercise to model a chess piece, a cup, or a teapot, I could see that being a potentially unassisted task. However, looking back to some introduction to 3DS Max material, they actually show you how to model an apple, some planets, and then a chess piece to get you started and familiar with the modeling process. There really has not been anything similar yet in the learning flows on modeling. I feel the same way about the exercise following the Fundamentals of Texturing course. Without having painted even a single, real model by step by step instruction, we are unexpectedly tasked with hand painting an axe. This task is near-impossible without first watching the summary video of it.
I personally believe there should definitely be a step-by-step tutorial to establish users in modeling a wheel, and then task them with creating their own wheel afterwards. (BTW, if you do make a tutorial for this, I think the treads should be modeled as one piece with the tire wall, as Andrew Price did. This way the tire can be more natural if desired and avoid intersecting geometry.) :-)
Thanks for your time in reading this feedback; I hope it will be helpful. I really have enjoyed the material on CG Cookie thus far, your thorough explanations of Blender, and I look forward to continued learning on here.
-Adam