Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Dust Sucker!

I am on my second copy of this lens. Both lenses accumulated significant dust underneath the front element within one week of owning this lens. It has a very poor feeling zoom operation. It's impossible to zoom slowly and evenly while shooting video. I love how sharp this lens is, even at 2.8, but it's inexcusable that Canon chose to not fix the problems surrounding the poor build quality for such an expensive lens. I plan on keeping this lens, because it's the best lens for a crop sensor. It pairs very well with my 60d. It's off to Canon for a cleaning after one week of owning. I plan on putting a UV filter from now on when it gets back from Canon. Last thing, its absurd that I have to spend another $50 on a lens hood because Canon won't send one with the lens. For $1,100, it should come with a lens hood. Think twice before purchasing this lens.