Do you have to have AA batteries in the unit even with a battery pack attached?
I suggest you don't do that. I tried using a 6000mAh attached with AA batteries in and it didn't work. The next time I went to power up the unit, no power. The AA batteries had leaked. Cleaned it up and it works fine now, though I haven't tried another battery pack. I'd say one power source or the other.
I prefer external mic kit.. Trigger is more sensitive, no need to move device forward.
When shooting subsonic 22lr, I put the unit back by the scope and the trigger mic on the end of a wood dowel or a green landscaping rod and duct tape that to my chassis. No muzzle/barrel interaction. Seems to work. A 308 with a BABC brake, no issues triggering from back by the scope.
The one I had was just too finicky for me. I got quite tired of fiddling with it. Magnetospeed for me.
On the Magneto versus the Labradar, to me it comes down to if you want just MV data and don't care where the bullets are going, versus being able to see what is happening with the bullet a little bit down range and no interference on accuracy/POI. The issue is that you really don't get enough distance data to be relevant for Centerfire larger rounds, and where it might be interesting for 22lr, the small bullet doesn't give very good tracking. There is also the issue with if you are at a public range and there are other guns going off.
If it had a wider envelope of operation- if you could just set it down and run and it consistently gave data- while you did your range time, that would be interesting. To me, it is too finicky- on triggering and tracking.
Mine works well with loud, braked 308 guns. Good triggering and good tracking. 22lr is another story. Lots of issues with tracking, getting data and only getting it out to 50 yards. I know, physics.
I have a real hard time aiming the damn thing. The notch is a joke. There is no way to confirm the aiming. They really need a laser or something a bit more exact.
If you are just looking for MV data, I'd just go with the magnetospeed, though that is the greener pasture since I haven't tried one yet. The Labradar nails the gadget seeking, gear obsession. The only thing cooler than lasers is radar. The data available is cool to play with.
If you do get a Labradar, get a mount that is stable enough that when pressing buttons, you don't push it off target.
(Is there a best setting for the 'delay'? I think mine is at 250ms?)