this be my second 4870 ; the first one work great as long as it work , which be not very long . after a little over two year it start smell and act like something be seriously wrong which happen to be the case . that 4870gz be sit in the garage wait for I to decide what to do with it . it may be repairable or not but I have decide to retire it . you may well ask why I would buy another one , well , that be a good question . I have never own a vacuum before that stop work after only 2 + year . I hope that this early malfunction be anomalous to that particular machine and not typical of the breed . while it work , it do a really good job , therefore I have decide to give the maker and the model one more chance , and I hope I be not sorry ; I could not find a pattern of early failure on this model on the web . I also have a investment in bag , filter and belt that I hope to be able to use . I 'll admit that I feel as if I be roll the dice but hope for much better result this time . the 4870mz have a additional feature which the gz model do not have ; the small brush attachment for clean stair . although we do not have stair we do have some small carpeted space that be too narrow for the upright ; this attachment do a good job in those area . the 4870 have do a very good job on we carpet , and be easily adjust for bare floor . I be please enough to give it one more try ; if this one only work for 2 + year I will write the model off as a lose cause . only time will tell .