First off, most of the people that review this poorly need to take a good look in the mirror. This is an under $25 juicer, not a hundred dollar juicer. That means you are going to be limited in what you can juice, overall design, power or build quality/life.
POWER:
Now if you read the reviews no one seems to complain about the juicer's power. Well I guess some do, as they complain it has too much power and can dance or spin. They also complain about too much pulp (because of the extra power). Now this many seem silly but with ANY high powered kitchen appliance you need to be ready to hold it in place during use. Perhaps you need to place it on non-slip mat to help control its movement.
DESIGN:
My thought is that people are confused on what this does. It doesn't take pieces of already cut up fruit in a slot like more expensive items. It instead does the twisting motion of a manual (normally glass) juicer so you don't have to. It also uses more force than you would to speed up the process. Because of this different design, it works well only for a limited amount of fruit--no carrots here, but what it does is produce more juice and pulp from oranges (and other citrus) than most other brands. I personally like pulp in my juice but if you don't you will need to strain it as it does not automatically do that. I personally like that because I can control the pulp amount more than if the juicer automatically does it.
Now some people complain about the design of the juice spout, it isn't tall enough for them or it is too tall or too small, etc. Well since the item can move during normal use and because the cup is small, I simply found a plastic container we had that was wide but not tall and use that. It can hold a lot more juice at a time, plus is able to be under the spout even if the juicer moves. If people would do the same, 80% of the bad reviews wouldn't exist. The way I look at it is this is a $50-65 value juicer with a few quirks to work around. If that means you need to strain your juice and purchase a larger wide collector container, then so be it. You will still be WAY ahead because of how discounted these are.
BUILD QUALITY/LIFE:
This does not feel or look like a $25 juicer. Heck it acts like a juicer worth way over double that. I haven't seen one review where this died which is very rare for kitchen appliances, especially since this isn't a new model. Based on the feel of its parts and its surplus of power during use, I expect this to have a very long life indeed.
So if you want a power juicer for citrus and understand the quirks of this and still want it, I say go for it. Juicers all have people complaining about something--at least this one saves you money due to its quirks!