JMHO,
While I know there are some diehard fans on both sides of the “best chrono” debate, each system has its positive and negative aspects so it depends on where, when and how you use them. I have both the V3 and the Lab but I find the V3 is much easier to haul around and the Magnetospeed is basically a single purchase for all you need. With the Lab, purchasing the unit is just the start. If you want a case to carry it in, a tripod to hold it up, and an extra battery for a prolonged session, these things are all extra. Sometimes I use the V3 and other times I use the Lab. They both give accurate results so it just comes down to individual preferences for the most part.