I recently purchased this chronograph after running a Caldwell chrono for years. The Garmin is worth every penny in my opinion. Easy setup, very small and compact, and so far it has never not receded a shot. I am very impressed with it.
I bought this about a month ago to compare with my Magnotech Chronograph. The Garmin is compact, can be carried in a pocket and is easily as accurate as the Magnotech mentioned. It also provides FPE which the other doesn't
I love the ease of set up, use and the ability to record, analyze and label data on the app via Bluetooth. It calculates power factor for you also. I'm sure there are a lot more features that I need to figure out but it's pretty much plug and play for the aforementioned features. Only knock is the price but of time and use equals $$$$, it just might pay for itself (lost points, match fees, time and not chronographing as often).
I have used multiple shooting chronographs over 50 years of firearms experience - including those from the US Military. I've used several brands of optical "bunny ears" chronos that fail to register if the sun is too bright, or at the wrong angle, or too dark, or if too close to muzzle flash, or if you put a bullet into the instrument, or .... Several years ago I threw out all the optical chronos and bought the magnetic sensor "bayonet" style. These worked SO much better... but they are a little fussy about how they are mounted, you must have the cable hooked up to the main body, they don't work for all firearms (e.g., revolvers and most handguns), and most importantly - can affect your shot placement because they attach (typically) to the barrel.
The Garmin is SO small, does NOT touch the firearm, is NOT fussy about placement, and works with ANYTHING that shoots! My first trial the day I received this was by holding the unit in one hand and shooting a .22 LR pistol in the other. The Garmin registered every shot without fail.
I next compared the readings of the Garmin to the MagnetoSpeed bayonet chronograph firing a 5.56x45mm MSR. The readings were very consistent with the MagnetoSpeed showing a slightly higher reading than the Garmin. I believe that is because the MagnetoSpeed is measuring the bullet's velocity inches from the muzzle whereas the Garmin is measuring over a longer distance. The readings were very consistent and closely tracked.
The Garmin is more expensive than the MagnetoSpeed - but SO VERY MUCH MORE convenient and quicker to use.
This is an extremely easy to use Chronograph that will change the way you shoot. The only issue that I had was battery life, but that was more about the user than the product. It hadn't been charged after 2 range trips (minimum 3 hours each) and midway through the 3rd trip, the battery died. The advertised battery life is 6 hours, so I'm very happy with it. It did charge quickly though. There may be cheaper Chronographs out there, but nothing as easy to use and portable as this.