Quality of Umarex T4E Walther PPQ vs Byrna SD

Has anyone had experience with both or either and can speak to the quality? I have found a lot of air pistol reviews citing the Umarex Walter PPQ as being very high-quality, but none of those review lists mention the Byrna, and I can't find a review of the two side-by-side on YouTube or elsewhere. The Byrna SD looks like it is of significantly higher build quality and materials quality.
I want to believe the Umarex Walter PPQ is of equally high quality as the Byrna SD however the price of the Umarex at ~$150 on Amazon versus the Byrna at ~$400 has me wondering if the build quality is significantly different between the two or if the Byrna is just overpriced.
Any advice or thoughts are appreciated!