The Corsair QX120mm is phenomenal, especially when it comes to RGB ... So 'mandatory' is a strong term for them, but you won't find many builds that don't use case fans. Can I Use Case Fans Instead Of ...
Personally, I've never had an issue with the iCue software itself. It sometimes eats up around 2% of my CPU usage, but it's got an easy-to-understand interface and the added benefit of PC monitoring ...