I normally use Kanji because no reason to use Hiragana or Katakana. If we use Hiragana or Katakana, it gives some impression. For example, gorgeous sushi restaurant like to use 寿し or 鮨. They never use すし or スシ. Some casual restaurant like to use スシ. すし is normally no use. 寿司 sounds like normal for me. Sometimes we use Hiragana and Katakana to give it casual impression on purpose. This is my opinion. Hope this helps.