No one ask, but here is my two cents.
The upside-down Caldwell seems to work better under low light conditions than any of the Chrony series (at least compared to my Alpha Chrony). I do have a light kit for the latter, but it isn't much help in my opinion.
I have a small Listone L1000 that works well, but the pass through is only 2 inches square limiting its use (and appeal).
Forget the Magnetospeed standard model as it won't work with airguns. It takes the V3 model to do that, and at about $375 for muzzle-only FPS, it is a bit pricy. And don't expect any accuracy at all with it attached.
I first borrowed a Labradar, but just could not get the thing to work as advertised. With some assurance that a new one would work, I bought one. It works very well for .25 caliber and larger airguns, but falls a bit short (lots of errors—no readings) for .22 and .177 calibers. It sees my .25 caliber out to about 75 yards, and my 9 mm out to about 125 yards, under low wind conditions. The drawback is the cost. With microphone extension kit (required for airguns), carrying case, bench mount or tripod, it is close to $700 delivered. This is offset a bit as you can easily calculate the BC with the data supplied by the Labradar (velocity at a number of distances). Is it worth the monies? Yes, if you do a lot of tuning for yourself, or as a group buy for a club. Otherwise, the Caldwell is on the tp of the heap.