User testing was carried out with a sample of 48 participants and results showed that all participants, despite having no prior experience with AR tutorials for furniture assembly, were able to successfully complete the tasks. High acceptance levels were observed for the assembly process in both devices, with agreement rates above 70%. Tablet users presented more consistent and shorter assembly times, while HMD users achieved higher assembly accuracy but reported greater discomfort and variability. The findings highlight the role of learning curve, task complexity, and user experience in AR adoption, and demonstrate the potential of integrating AR and AI to support assembly tasks in DIY furniture and bigger scales.