Keep in mind that this mower is 14" wide. Which is not much more than one foot wide. So if you have a "real" lawn just imagine how many trips back and forth you will have to do across your lawn. If you live in anything larger than a townhouse this is too small. If you really do not want to purchase a gas or electric mower, look at the larger push mowers (18 or 20in) but not this one.
If you have a small area to mow, this is a great option. I bought this for my 110lb girlfriend who has no trouble pushing this around her tiny fenced in yard which is probably 15ft by 15ft. It is easy to manuever around and only takes a few minutes to mow the grass. She has an electric trimmer which she uses along the fence.
As others have mentioned, it doesn't cut through twigs and branches very well unless you get some momentum going. And it does tend to leave random blades of grass sticking up that it doesn't like to cut. These blades are usually longer than the rest of the grass or are a different type of grass. But once you have the lawn a fairly uniform length it does a good job of maintaining it.
So if you have tiny yard, this is a very good choice for you. If you have a medium or large yard, this is not a good choice.