Things I liked: These units are very picky about a light source. You will spend many hours being frustrated by this design flaw.
Things I would have changed: Buy a better chronograph from a more reputable company.
What others should know: After a year my display had problems but they won't honor their warranty. The Shooting Chrony company is a disaster to deal with. DO NOT BUY A SHOOTING CHRONY PRODUCT. You have been warned. Their customer service is the worst that I have experienced. They should take a lesson from PA on customer service. PA has been great!