Been thru many of the common chronos. Ones that attach to the gun barrel, probably it's just me but they feel awkward/funny {balance) and seem to change the impact point. Plus I can't use them with my handguns. Chrony style (light sensors), like my Oehler 3P, take way too long to set up and align to target, very bulky to take to the range, especially when taking it out to the field. If at a public range, I disturb other shooters when I have to ask them to stop shooting while I set up. Of course to be nice I let the other shooters try it out, but that extends the time I spend at the range while everybody gets a chance to shoot over it. And that time is further extended trying to explain to everyone how to get the proper sight alignment to avoid blowing away one of the sensors, which has unfortunately happend a few times. Then the chrony styles are all dependent on decent lighting, again, maybe just me but it seems the indicated speeds vary as to whether it's bright sunlight or cloudy. Adding artificial light bars for consistent lighting is just one more thing to carry and set up. Now my Labradar, I take it out of the bag, set it on the bench, align to target and start shooting. Less than a couple minutes between arriving at the bench and first round down range. Works every time regardless of light, bright sun or heavy clouds. Can use my pistols or rifles, no difference.
I guess it should be clear that for me, until something else comes along, the Labradar is my choice. Unfortunately I've spent far more trying other chrono's than I spent for my Labradar.