Is the AF-S 18-200 mm lens bad?

I was going to get the AF-S 18-200 mm lens for my Nikon D5100, but then I was told that it isn't that good because it is slowe, it is not as sharp as a prime lens, there's more distortion, you won't be able to get as much wide zoom range, you cnat photograph in low light. Is this true?

Added (1). I want to be able to zoom in for pictures as well but I don't really want to have to carry so many lenses and they are really expensive.

It's a good walk-about lens that allows you to avoid swapping lenses. Your shots won't get in National Geographic, but unless you have strong requirements for state of the art imagery, this lens will serve you well. Also, there's nothing magical about prime lenses. Yes, they are sharp and optical compromises are made for zooms with wide focal length ranges. But 99% of the viewers will still love the photographs from your 18-200 if you used care and skill or captured a rare moment. The skill of the photographer far outweighs any technical advantage of the gear.

It is a multi-purpose lense. Of course when you put wide angle & zoom together to make this & its price range, there are trade offs such as theses
1: variable aperature as u zoom. 3.5 @ 18mm ---> 6.3 @ 200mm. U loose some light when zoom out… In low light (late afternoon) without flash you will suffer.
2: Having so much zoom reduces image quality (contrast, sharpness, etc… )

3. Nothing beats prime lenses, but are you willing to move? Do you have time to switch lense so often. This is why pros cary more then 1 camera. Less / no zoom, & good quality, but have multiple cameras because they don't have time to swap lense

It's not dramatically bad. It's good enough as a first lens for someone who's afraid to change lenses or as a travel light lens for the more advanced photographers.

Personally I think it's too expensive for what you get. As a starter I'd say get a 18-105 and cut your teeth on that.