I bought this cable to replace the Joytech version, which was giving me a shadow/offset effect when using the 720p/1080i display modes.
The Microsoft cable produces a fantastic clear image, without the abovementioned problem. Unlike the Joytech version it doesn't come with an optical lead included, and is slightly more expensive, but the image quality is worth the extra money.
The official product definitely wins hands down in this case.
ps After originally being put off by a 7-10 day delivery time (due to shortages in the UK), I'm happy to report that Amazon had it with me inside 48 hours. Excellent service.