I'm by no means a professional, or expert that being said, with the research I've done the firmware and software for these digital scopes seems to be what makes or breaks them, and the warranty. It seems that Thay are all prone to freezing up and needing to be reset no matter the cost. The illumination brightness and resulting eye strain would be a factor for me, along with field of view, battery life, weight, Ease of use, and the cost. Some states don't allow the use of digital scopes for hunting, so if you plan on that, check your states regs. the price of oneleaf NV 400 and the features are appealing for sure. The pard and oneleaf nv100 clip-on units allow you to use your favorite scope reticle and can be used as a standalone unit for night spotting, but the recording and field of view magnification is lower quality, and the scope eye relief. Setting up and aliening can be a pita to get right. In my mind, there is no free lunch with any of these units.