With extensive use of Labradar I will echo that it's only real con is that the accessories above should really just be part of the unit Most noted being the addition of the trigger Without it it is unreliable .Plenty of folks have issues it seems with shots not registering. A external trigger seems to be the ticket, most just use velcro.
I've personally not had any issues after thousands of rounds......maybe 15 missed shots at the most....guessing.
Once you have it set up with the appropriate accessories it's valuable tool.
To overcome some of the cons of a magneto speed, (like a stock mount so it's no on the barrel) you will incur additional costs there also. So if your comparing devices to get best performance, I suggest evaluating each on its own merits as they are both good but both require accessories to really work well.