In the light of @dhh's recent presentation at #railsconf you do well in remembering this section from @37signals' book Getting Real:
“You take too much of a black and white view.”
If our tone seems too know-it-allish, bear with us. We think it’s better to present ideas in bold strokes than to be wishy-washy about it. If that comes off as cocky or arrogant, so be it. We’d rather be provocative than water everything down with “it depends...” Of course there will be times when these rules need to be stretched or broken. And some of these tactics may not apply to your situation. Use your judgement and imagination.