Some days I do, some days I don't... either way I can still style my hair because it's always damp when I do so, which is the key to making it easy to comb through my hair type.
Conditioning mainly makes your hair look 'nice' in general, and it might contribute to a little moisturization of your scalp... otherwise it's not essential in my book. Especially if you're following up your shampooing with some Tricomin or Folligen.