Just like Tox said, the Truxxx is a spacer lift, this is a cheap lift for height, nothing wrong with it, it just isn't performance driven.

The (still) Donahoe (& ICON they are a combined company now) is a performance lift, this is a replacement shock with coilspring that is adjustable for height. The ride on the Donahoe/ICON coilovers will be different, but more performance driven, than stock. If you plan on taking the truck offroad, want to have control at speed on dirt/washboard roads or just plan to be off the pavement, the D/I stuff will be designed based on this.

If you are a pavement pounder and don't plan on taking it offroad then the Truxxx lift will be just fine for you.