The HTC One is terrific, fast, has a great display and fun, because everything runs quickly and smoothly. The camera is top and makes great photos in dark environments. The sound is like nothing what there is to this day in a cell phone! It is amazing what a sound comes from the two front speakers. Here HTC is truly new standards. The housing, and the entire device is pure quality and looks very robust.
Just buy it for someone who is looking in this price range for a cell phone. Unlike Samsung, HTC has also learned and their own surface kept deliberately simple. The surface of Samsung works for some time to playful and colorful (but which is known to personal taste) ;-)