I'm going through this right now. I purchased the bottom of the line Caldwell, under $100. The phone software is simply awesome but the problem is, the chronograph, overall, is extremely sensitive to light AND to battery voltage. If you're out at the range testing for say four hours, the software will drain your phone's battery in half that time unless you run in low power mode. I have a new iPhone 12 which has exceptional battery life and I was down to 20% in low power mode afte said 4 hours.
On the light issue, it MUST be in the shade. I'm in Texas where it's most often sunny. Does not like sun. Since I'm often shooting in the morning or later in the evening, the sun comes in at an angle and the shades don't offer any assistance. I had wild readings all over the place after getting a good setup for it in the shade and it doesn't really like .223 but 308 was consistent and I was able to get good strings of readings on all five shots per test round for several different loads. And again, the software is great. You type in the bullet and any other details you want to and it automatically records each shot until you hit stop, making all he calculations for you. You can then save the data and pull it back up at any time like later when you're at home looking at all the details.
I set mine up on a very beefy tripods I have lying around (former photojournalist) and it's stable as hell. But it's a pain to set up and if you get an ERR reading that won't correct, I have to ask for the range to go cold so I can flip the switch on and off. I honestly hate interrupting anyone else shooting so I want to eliminate that altogether.
So now I'm looking for something more consistent and I believe everyone has brought up the relevant models above.
Cost-wise, for me, I cannot afford the Labradar at this time as cool as it is. I have a lot of other things on my purchase list so I have to compromise.
The MagnetoSpeed V3 looks like my best option from a cost standpoint and it's a bit over actually. On the POI shift, is it consistent? If I go out there with a load to determine speed and groupings, is it workable or is it changing POI shot to shot? I'm assuming I can always dial in the POI later without it on or am I missing something? How's the iOS software? Decent?