Minolta version is without any doubt a much better lens in terms of optical quality and body construction. Quality of this zoom is very good. My advice is to decide which lenses you need or will need in the future. Once you decide on the focal length, see how much you are willing to pay for a lens. In this case, buy the best one in terms of quality and construction.
Longer telephotos are a different story.
Buy the best you can afford. If you can pay more for a 300mm or 400mm, either fixed or zoom, you'll see the difference in quality. If you can't spend more, a good budget telephoto lens can produce quality results if used properly. The good thing about modern lenses is that quality have been improved while prices have gone down. It is now possible to take good photographs with any lens.