My chronograph cost about two bottles of Laphroaig, so it is hard to say which is the most essential for load development for money spent. Laphroaig is more for the cerebral development stage, however....or lack thereof. Whatever works for you.....
However, my Shooting Chrony Master F1 is accurate and consistent if you shoot it in consistent conditions....WHICH IS.... a bright sunny day with the sensors shielded from direct sunlight.
It will give a different reading on a cloudy day or if direct sunlight is in the sensors. So shoot under a standard light condition, bright and sunny, not very early or very late in the day, and the Shooting Chrony works very well.