This is a good OSD for the price, but it's not on par with some of the more expensive OSDs out there. I've got the V2 version. The speed seems reasonably accurate, but the altitude does not. You can see in my latest video that I start out with the altitude at zero, when I land at the same location, it's reading +300m(altitude is on the right ladder). Maybe the newer versions have fixed this, but I haven't heard any reports of it yet.