I use the Yaqi slant more than I use my R41. I know it's hard to believe, but it's true. I even use the Yaqi slant more than I use my Fatip open comb slant. The design and quality are both excellent. If I could have only one razor head, the Yaqi slant would be it.
For me it's way too aggressive and uncomfortable to shave, so it's definitely not a keeper. Build quality is good for the price of 4 USD, otherwise below average.