I started 20(?) years ago with a Shooting Chrony unit and it worked fine as far as I could tell until a friend shot it while testing shotshell loads. I replaced it with a Pro Chrono analog unit and enjoyed using it without drama for many years.
Then about seven years ago, I decided that I should have a "better" chronograph and bought a Pact. I couldn't get as much as an error code out of it and after using up almost all my rifle test loads trying to get it working, I following the urgings in the owner's manual and called Pact at 10:00 a.m. their time on a weekday from my gun club.
Almost two hours later, someone finally answered the phone. When I told them the range faced west and the sun was behind me, they said that was the problem and that I should position the unit so the sun was shining directly into the photocell openings. When I then told them that would have the unit turned across the range and tilted back toward me, they said, "You gotta do what you gotta do." I did - I returned it.
I then bought a CED M2 direct from CED, a Pennsylvania company. It's a very nice setup but I got lots of goofy readings from it that were obviously erroneous as well as error codes with no readings. So I called CED and spoke with an oriental lady who tried to help me but wasn't successful. She finally told me she would have their chief engineer, Charles, call me when he returned to this country.
Over the course of about two months, Charles sent me replacements for every electronic part of the unit without improving its operation. He tried his best and when I kept telling him that I had started setting up my old Pro Chrono in line with the M2 so I would get readings and not waste test loads, he told me that their chronographs use "better" photocells that are more sensitive to lighting than those of cheaper units. I maintained that decent readings beat not getting any more exact readings and he finally agreed to accept the unit as a return.
I then bought a new digital Pro Chrono and haven't had a glitch yet, six or seven years later. And now Pro Chrono has a Digital Link Bluetooth adapter that transmits shot-to-shot and shot string data right to your smart phone (
Bluetooth Adapter - Digital Link - Competition Electronics).
I have that as well as the bench-mounted remote control (which I no longer use since getting the Digital Link) for my unit and could not ask for better service. It may not be as dead-nuts accurate as chronographs costing hundreds more but for the average casual handloader like most of us, it's plenty good enough.
Ed