Have no experience with the Oasis. I have a set & forget in my mini. I also have a DX drawer in the mini so there is a bit more volume to keep humidified. The humidity stays dead on at one degree below the maximum setting (so, if I set it at 70, it almost always reads 69). Remember that the set & forget is calibrated at +/- 2 degrees for RH. I think mine is probably at about -2. I attribute the rock solid RH level mostly to the quality of Dave's cabinet. That said, the set & forget quickly and easily corrects and maintains the humidity level wonderfully. For example, when I keep the door open while choosing a cigar, the system comes on and corrects the humidity quickly.
One thing I did was to move the reservoir unit to the top shelf, which is more in the center of the unit. I think that way, the set & forget better evens out the variations in humidity that occur through the vertical of the unit. A drawback to doing this is that the top shelf does not go all the way to the back to fully support the set & forget