It is quite important to keep the lead in the middle of the jaws for accurate AC and DC currents measurements.
The recommended procedure for DC is to clamp the cable, remove the clamp, zero the reading with the Relative button and remeasure the current with the conductor in place again.
In my experience, measuring DC milliamps is quite difficult, with a fair amount of hunting around the real value. AC readings seemed easier, with more accuracy and less fluctuations.
I did adjust the DC voltage through the VR1 trim pot on the lower board, as it was reading slightly below my other meters.
There are 5 trim pots on the upper board, VR7 and VR8 adjust current readings.
More expensive meters have additional features, like USB or internal logging, higher counts, wider jaws, higher currents measurements, True RMS AC+DC, Max/Min, 3-phase measurement capability, bar graph, low-pass filtering, inrush current and more, so make sure you know what you need, before you buy.
So, to conclude, I am quite happy with this purchase, but it is no real replacement for a normal DMM to measure currents below 10A, as a decent accuracy is difficult to achieve. It will be handy in some special circumstances, when the current leads cannot be connected to a normal multimeter for instance or for use in a difficult environment, where accuracy is not that important.