I have use the PowerBlock Classic for about 4 week now and I have to say I have not be disappoint . I purchase the set because I start with the p90x exercise routine and they require you to use a number of different weight to do it correctly . the PowerBlocks enable I to change weight quickly and keep up with the video instead of have to pause and change weight . the weight feel comfortable and solid when you be do you exercise . I wholeheartedly recommend these dumbbell .