Comments on the Leica Disto D3, now that I have 2 years experience of using it heavily:
1. Functionality is good, as expected.
2. Battery life can be a problem – certainly turn it off between every shot, and don’t keep the laser running longer than necessary.
3. The ‘maximum-distance’ function, potentially excellent for those shots to inaccessible narrow tube far-ends, needs care. It works, but occasionally will give readings way too high. I think this is a reflections issue – the incorrect readings may be double and triple the real distance. The solution is to apply reality checks, and repeat the measurement as necessary.
4. I am on a warranty-replacement unit – my first one gradually developed a problem where the clear/off button did not work. Warranty was ‘no-questions-asked’ – nice.
5. I am currently experiencing another problem: sometimes the laser does not turn on! A good clout always fixes it, so perhaps a bad connection? It’s not the battery connection, as the unit is otherwise fully powered up and functional. I suppose this problem, and above in (4), may be related to the harsh environment in-cave.
6. A great design improvement would be for the ON button to require a long press, as does the OFF button, since it frequently gets turned on accidentally in a pocket: VERY annoying!. Most of the time I carry it in a pelican case with my compass and target-lamp.
7. I wish it used AA rather than AAA batteries.
Summary: Overall, an excellent purchase.