From a CPA in California:
One if my clients sent me the article you wrote about The negatives of Sub-S corporations. With what you say you have some valid points i.e. the used of Multiple Section 179 deductions. Which would be valid if you have a machine shop or other company with a lot of new equipment purchases.
What you did not mention is the high cost of Social security taxes (15%) of the earned income also the Double taxation of retained earnings distribution and the deferred taxes for the retirement contributions.
While I can see why you did not go into detail on them you should least give them mention as being considered in the overall picture of the clients tax situation.
If I can be of any help please call or e-mail.
Having to address each of those issues, plus dozens more, is the very reason I insist that nobody make decisions on what entity structure to use without consulting with a qualified tax pro.
Thanks for writing.