The Prochrono DLX is amazing.
I fired 5 shots through it today, using the phone app to gather data. I was surprised to hear the phone announcing the velocities aloud. That sure beats turning around to read numbers.
Unlike my old Chrony, the Prochrono worked every time. The app let me save the shots in a list which included information on OAL, powder type and amount, and so on. It recorded the temperature and barometric pressure, too. When I was done, I used the app to send myself a PDF. It has the average, standard deviation, and a bunch of other stuff laid out for me.
The Chrony was better than nothing, but I would never buy a Chrony product again. I bought mine around 10 years ago, and it seemed junky even by the standards of that time. It's a pain to use, it can't connect to a phone or tablet, and the company that makes it does not pay any attention to emailed orders even after soliciting them on its site.
The Chrony's diffusers are weird plastic things you have to snap together. The Prochrono has one-piece diffusers that can't come apart on you.
I'll keep the Chrony in case I shoot the Prochrono, but even then, it would only be an emergency backup.