Been using my Labradar for a while, mine was from the first shipment. Still use it very frequently.
There were a slight learning curve with it, but it's been solid. Was previously using a Magnetospeed but noticed it did throw off ladder/OCW tests slightly, especially on lighter profile barrels-- the Labradar lets me get MV/ES/SD numbers during load development without possibly skewing a ladder test.
A few observations:
Make sure your tripod or base is sturdy, the Labradar acts like a sail in the wind and I've heard it doesn't take falls or knocks well. If I'm shooting prone I use either the Labradar base or one of my Slik tripods set as low as it will go and haven't had any issues. If shooting from a bench, I use a heavier manfrotto tripod or labradar base and then tie them to the bench with a length of paracord so it can't get knocked or blown over.
As mentioned, battery life with alkaline AA's is terrible. Lithium AA's slightly less so, but still not great. Get an external USB pack or use Kentli 3000mah AA Li-on rechargeable batteries; cheaper just to get an external USB battery pack though, the Kentli's aren't cheap. No worries about possibly damaging the micro USB port with them though.
If someone is shooting next to you with a brake be prepared for a lot of false triggers. Also be prepared to hit enter every time that happens to acknowledge the "projectile could not be tracked" message that pops up. You can play with the trigger level sensitivity to help with the false triggers, but they still happen occasionally. I'm still waiting for Labradar to make that an automatically resetting warning message in a future firmware update (hopefully at the same time they enable the already built-in bluetooth functionality and release the matching phone app.)
The smaller the bullet, the more critical the aiming-- especially with .17 and boat tailed .223. I bonded a small section of plastic tubing into the sighting v-groove on top of my unit to make it faster and easier to aim-- like boresighting. Some people use a small construction square set against the front of the labradar to aim it, I've seen others take it even further by mounting low power scopes to their units... I don't find the aiming that picky, but the little v notch is barely adequate IMO.
Triggering the unit can be a pain with PCP air rifles and I'd imagine suppressed rimfires (can't say about that, no suppressors here in CA.) The external mic kit solves that, but for PCP air rifles with very effective moderators I have to get the mic close to the muzzle and take the foam gust guard off the mic to get it to trigger reliably.
Be careful shooting next to larger calibers in cold weather... the muzzle blast from a 7 SAUM cracked the case at the upper corners on my unit when doing load development on a 32F morning. I had the unit well aft of the brake, back near the ejection port, and the brake on the rifle did not have rear-angled ports. Cold weather, plastic with a large surface area, and overpressure just aren't a good combination. The Labradar people fixed it for no charge and said that's something they hadn't seen before.
Other than that, the Labradar has been the only chronograph I've used since receiving it. My magnetospeed only occasionally gets used for quick checks of friends rifles, and I sold my Oehler.
