I got mine a couple of weeks ago and my experience parallels those above. I also missed a few shots when I had it too far back from the muzzle and last week was chronographing handguns along with rifles and missed a few shots when I forgot to switch from handgun mode to rifle and vice versa.
I too, tried the doppler mode and it didn't miss any shots but you're right it does use up batteries pretty quickly that way.
I don't know which base model I got but the ball joint tightens down well and holds the unit steady.
