Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great Images, But Mildly Disappointing

What's great about this lens is:1) Sharp images with great color, imperceptible distortion, no fringing. This is really what it's all about, right?2) Lens front does not rotate when focusing, allowing the use of polarizers and graduated ND filters. Rarely found in a lens at this price.3) Excellent price, which leads to a great value.I'd wish for (even if it costs more):1) More solid construction, as mentioned elsewhere,2) A USM motor - the lack of which means this lens is slower to focus & a bit louder compared to Canon's USM lenses, and3) Full-time manual focusing ability. (The USM motor would fix this too.)Every photographer should have a "nufty fifty." For the price, this lens should be in every EOS shooter's bag.