Many studies have confirmed the benefits of using Augmented Reality (AR) work instructions over traditional digital or paper instructions, but few have compared the effects of different AR hardware for complex assembly tasks. For this research, previously published data using Desktop Model Based Instructions (MBI), Tablet MBI, and Tablet AR instructions were compared to new assembly data collected using AR instructions on the Microsoft HoloLens Head Mounted Display (HMD). Participants completed a mock wing assembly task, and measures like completion time, error count, Net Promoter Score, and qualitative feedback were recorded. The HoloLens condition yielded faster completion times than all other conditions. HoloLens users also had lower error rates than those who used the non-AR conditions. Despite the performance benefits of the HoloLens AR instructions, users of this condition reported lower net promoter scores than users of the Tablet AR instructions. The qualitative data showed that some users thought the HoloLens device was uncomfortable and that the tracking was not always exact. Although the user feedback favored the Tablet AR condition, the HoloLens condition resulted in significantly faster assembly times. As a result, it is recommended to use the HoloLens for complex guided assembly instructions with minor changes, such as allowing the user to toggle the AR instructions on and off at will. The results of this paper can help manufacturing stakeholders better understand the benefits of different AR technology for manual assembly tasks.