I did have some trouble with one of the bolts during assembly, but once finally assembled this is a strong sturdy design.
I was a bit sceptical about buying one of these door bars as a lot of the reviews i have read had people complaining about how they would not fit them in their door frames properly. After searching around a bit i noticed that this door bar, although the same design in the pictures as others i've seen, stated that it should fit most 24-32" width doors. Unfortunately none of the designs state how deep your door frame can be which is the worry i had as my door frames are all 7" deep. But i decided just to go for it and if the worst had happened i would have just got a refund. Thankfully my instinct was correct and it operates perfectly, all i need now is to actually use it all the time :P
Also, i am 6'4" so i was a bit sceptical about how close i would be to the floor whilst fully extended during a pull up, but all i have to do is bend my knees a bit and its fine :) also doing this helps strengthen my stomach muscles :D. Hope this helps