I measured with a thermometer, and unit cools well. The "4" setting, as they state in the manual, is appropriate for regular use (keeps the fridge compartment at <40deg F, which is the recommended setting for food safety). The separate freezer compartment was my primary reason for getting this fridge, and it works well.
Much like the 4.3cu-ft Insignia fridge that has a lot of reviews about units arriving damaged, my unit came with damage on the side that, based on the intact condition of the shipping box and styrofoam packaging, appeared to have occurred before shipping (poor QC it seems). I decided to go with the 3.0cu-ft this time, because there were a lot less reviews complaining about damage compared to the 4.3cu-ft one. Guess I didn't get lucky. And although smaller, this fridge is actually less energy-efficient than it's 4.3cu-ft cousin. But both are Energy-star rated.
The advertising says this is 3.0 cu-ft while the manual says it is 3.1cu-ft, with most competitor offerings in the 3.1-3.3cu ft range. So I'd say it's slightly smaller than the others, but I doubt anyone can actually tell the difference. They pretty much look all the same on the inside.
Compressor has a buzzing sound to it that makes it a lot more annoying than that of my old GE compact fridge, which emits more of a hum. Yes, my fridge is level. So I'd say it isn't appropriate if you're sticking this fridge in your bedroom (e.g. dorm room) and have sensitive hearing - at least I wouldn't be able to sleep with it nearby.
Overall, I'm satisfied with the unit and can accept the flaws given that it was less expensive on sale than all the other comparable units I looked at.