I use the top of the line PACT. The infrared kit sure beats hanging bulbs like the good old days. Outdoors even the sun going behind a cloud can affect your results. It will run on two 6 volt lantern batteries if you have no power. Other pluses are the printout of all your info. None of them are perfect so get the best one your pocket can stand, but for goodness sakes stay away from the cheapies. Look into what the cost is to R&R the skyscreens.....for certain you shooting buddy WILL hit one. We use mine indoors to ensure the competitors are making power factor. All in all, ask around & watch someone use one.
The PACT has been a workhorse.....helped me get my degree(ballistic sciences). The BIG drawback is the cost of the heat sensitive paper you will need for printouts. Note that the printouts fade with time so use a log book like the one MTM sells. A good chronograph will make you a better shooter & reloader! The PACT Pro comes with the infrared & screens built into the kit too.