This is just speculation, but I think the alignment of the source and receiver are trickier to execute than we may realize.
I had a Swaro that was reliable to 2000+ yards on just about any object, under any condition other than fog. Others, with the same make/model reported less and sometimes much less performance. Same design and components, but I think they differed in their alignment or calibration.
My first 1600B flat out sucked. It struggled to range trees at 1000 yards. I asked Leica for a replacement, and that replacement to be tested by a human outdoors. The replacement 1600B can't compete with a 'good' Kilo but overall does great for me and nearly as well as the Swaro while being smaller, lighter, and giving temp, pressure, and angle of the dangle.
I recall some posts at other forums where several Leica dealers were personally testing Leicas and selling the 'good' ones and sending the others back.
And for the record, Swaro customer service was great. The Swaro LRF leaked, but they got me a loaner and refurbed mine.
