I have the Magnetospeed V3. I have not spent much time reading reviews, but it has worked great for me. no complaints. Far more accurate and consistent than my old light-sensor chronograph that was more or less good for nothing compared to the Magnetospeed.
The Magneto seems to be the range right now. I have not used one yet, but I want to. I have a Shooting Chrony that has been super reliable for years now. I do a few other things that require a chronograph ( like pistol shooting and archery) where I don't think Ill be able to get the V3 to work. If this Chrony ever dies, Ill look at the CED M2. Those are used all over the world for National level pistol matches.