I use a R. H. Designs "ZoneMeter" which I bought in the late 1990's. I'm not sure on the operation of DA's Enlarging Meter, but the ZoneMeter is very easy to use. The ZoneMeter doesn't have a numerical display, but instead a row of LED's.
1. Place sensor under the darkest part of the negative (the highlights with detail)I find that the ZoneMeter gives me a very good ballpark place of where to start, or if I just want a straight or proof print. If I want a very good print, I use the ZoneMeter's suggestions to make a test strip which includes 15 seconds somewhere in the middle of the strip, and then change the paper/filter grade if needed.
2. Adjust the lens aperture until the first light on the row of LED's just lights up. This setting is supposed to give you a 10 second exposure w/VC filters 1-3. I find that 15 seconds is about right for my paper/developer/enlarger combination.
3. Place the ZoneMeter sensor under the thinnest part of the negative (the shadows with detail). The LED's give you the suggested paper/filter grade.
I would imagine the DA unit would work in a similar fashion. I could definitely live without an enlarger meter in the darkroom, but for me it does save time and paper.