We have used this for a couple of weeks now, and the three of us that use it all agree it does it job very well. The tallest of us is 5'10, so we can not comment about the others who are tall not liking it. We did not notice any smell what so ever, it seemed to be a little rough on me (skinny bony back), so I added a doubled up towel and it's now perfect. The programs vary and so far the three of us are impressed.
Good chair for the price. Definitely gives a vigorous back massage. Foot massager is mediocre, but it is relaxing. Seems to be a high quality chair. Air bags are ok, but nothing wow about them. I think the 6'4" height rating is a little high. I'm 6'2" and I have to slouch a little in the chair to get the neck massage. For the price, I'm willing to slouch a little, but really the max height should be 5'10" to 6'00". This chair isn't perfect, but it does the job and appears to be high quality for the price.