I have had shooting Chrony [Canada] and I have had pro chrono [China], and I like pro chrono better.
The problem I have with chronographs is that I shoot them with handguns.
The solution for that, for me, is to just shoot rifles over them.
The other problem is failing to trigger. I shoot, but the reading stays the same. My Shooting Chronies only trigger half the time. My Pro Chronos trigger all the time.
On accuracy. There is an error if the bullet does not fly over the chono straight. That straight vertically and straight horizontally. The would sum in some kind of three dimensional Pythagorean theorem.
The error would be proportional to the secant of that included angle.
The error caused by the chrono would be things like the error in the distance between the the photo diodes, the error in the frequency of the quartz crystal oscillator, ect.
Those errors are pretty small, compared to the spread between shots.