I've used the Magnetospeed, and although the concept is good, there are too many applications where it won't work for me to want one. Think full length tube magazines, light mounts, muzzle brakes, etc. I have a 35P, and I like it, but it can take a while to set up, and it can be negatively affected by atmospheric conditions. The chronograph that has my attention at the moment is the Mylabradar which is just now coming into the marketplace. Price is similar to the 35P, but uses Doppler radar to measure the bullet velocity, rather than measuring the time it takes the shadow of the bullet to cross 2 or more sky screens. Thus the Mylabradar set up is quicker, and is less likely to be affected by the changing light of atmospheric conditions, like variable cloud, fog, rain, ice crystals, snow etc. It could also be setup out of the way down range if you wanted to get a velocity reading at long range to confirm your bullet's BC, without risk of shooting the instrument.