Pretty much any variable aperture zoom (especially one of such a large range) is going to have worse performance than a prime of the same focal length. However, the construction of any zoom lens varies, so "bad" is completely subjective. It will likely be up to par for 35mm 8x10 prints if you don't shoot it at f/4 or below. Shooting it at f/8 will give you reasonably good performance, provided the lens is not malfunctioning.