class DirtyInformation

I just sent my coworker and email tried out some of the ideas out of my post from two days ago. I sent it to him with a little blurb at the top saying that I'm trying out a new method of code review, and I would love his feedback on it. I would also like some feedback from all of you. Should I word parts differently? Should I scrap the whole idea, and start over? Where can I improve? Do you have any techniques that you find useful?

The files and names have been changed to protect the innocent.

FooController

Lines 235, 236, 237 is there a reason why we are raising exceptions here?
When finding by id why did you choose ActiveRecord::Base#find and not ActiveRecord::Base#first?
Is there a reason for choosing a polymorphic relationship and not Single Table Inheritance(STI)?
How could add_comment(265 to 282) differ if you used STI?
Is it possible to utilize both polymorphic and STI, are there any advantages to doing that?

CommentNotificationTemplate

Line 13 - Any reason why this isn't using some kind of url helper method?
Line 13 - Do we need this line at all if there is a helper method to be used in the template?
Lines 28 - 30: Why is this static method even around?

html.erb
Line 12 - Can we use a helper for this?  Or make a route?

text.erb
Line 8 - Same questions about the url that is assigned in the controller.

In the tests there is a factory being used, but everything the factory includes is overridden.  Is there a reason?

The story template test could really benefit from a url helper.

Francis, this is great work.  I love to see that you got rid of the comment fixture.  I think this is a big step in the direction we need to go.  Your code is getting better all the time.  Keep up the good work.

The follow question was used to provoke thought from the reviewed "is it possible to utilize both polymorphic and STI, are there any advantages to doing that?" I just want him to think with that one. Is this a workable tactic? I would love to help him continue his amazing growth.