I run mine 24/7

I purchased my first XJ-2000 roughly a year ago.
My husband and I are both smokers and we own two large dogs. My goal when purchasing it was to keep my home from smelling like smokers live here.

The first one I purchased was to cover a area that is an open floor plan, a living room, dining room, kitchen area.
I knew from what I had read about them that this particular model wasn't really designed to cover that large of an area. It is more suitable for a 270 sq ft area for dust or pollen. Closer to 600 sq ft for odors.
But I wanted to see how well I liked it before purchasing more or a larger unit. I have been in buildings that have large units and actually gave me a fuzzy head feeling that I wanted to avoid in my own home. My experience with the XJ-2000 has never been that fuzzy head feeling, probably because of the space I am using it in.

This particular unit comes with both an a/c plug for home use and a car adapter that plugs into your cigarette lighter. I have infact used this in my car before with great results. I found that the every day odors and smoke odors were removed within a day of placing it in the car.
Once when my basement was smelling musty, I placed it in down there for about 3 days, since the room size is much more than 600 sq ft. When I returned, the odor was not noticeable anymore. I removed it and the odor has not returned.

Recently I purchased my second one to help cover the areas I mentioned before. One did a decent job but for the three rooms in my open floor plan, two was really needed.
I have had non smokers come into my home and tell me they would never know we smoke. I find that a little hard to believe but that is what they say.

The size of the XJ-2000 is 3.5"H x 7.5"D x 12"W and it weighs roughly a pound and a half. I have one sitting on an end table and one on my kitchen counter. They don't take up much space. Sound wise is very quiet! A slight hiss sound that in my opinion is soft enough to let you know it is operating but not noisy enough to distract you.
The models I have are a plastic material that is a light black color, not a shiny finish but more of a matte finish.

To use the unit you simply plug it into an electrical outlet in the room of your choice. On the side you will find a power button and a high/low button. There are lights to indicate if you have it on high or low. To clean it you will find two knobs on the bottom that simply unscrew. Once you have loosened the screws a metal plate slips out that needs wiped down. I usually use a wet paper towel and sometimes scrub it lightly with an old toothbrush to get in between the plates. Takes only a minute maybe to clean it all up. Putting it back in takes a little practice. Sometimes one side will go in correctly and the other won't fit in right. But with a few tries you will soon get the hang of it. I find I need to clean mine roughly every two weeks. If it needs cleaned and if you have neglected to do so, you will hear a sound from the machine that sounds sort of like a bug zapper, it is rather annoying and really gives you an incentive to get it taken care of.

There are no filters to buy for this which is a big plus. The cost of the unit, which you can find on ebay for usually around $40, and the cost of electricity is all the expense you have with this. I have read the annual cost to operate is roughly $5 a year if run 24/7.
The manufacturer suggest this unit will help with tobacco smoke, "old house" smell, chemical odors, animal odors, etc. The one thing I have noticed however is if you use it in a room where you burn candles or tarts, it defeats the purpose of the pleasant smell of those since it basically kills the smells in the air. When I use something like this, I usually turn the units off for a while.

I personally have been very pleased with my experience with it, in effectiveness, quietness and ease of use. I have not experienced any negative health effects from ions being released into the air. I suggest educating yourself on the pros and cons of such before making the purchase. I don't feel it is my place to educate the public on that in my review. Take the time and read up on them and then if you decide it is something you want, I recommend this particular model.