I have 2 sets of the robart spring down retracts and they do operate a little faster than what I would call scale, however they work very well and are very strong. The air valve can be adjusted to change the speed to an extent . I couldn't find the URL I was looking for but I did come across this which is close, you can't get much closer to scale than these, but I think there on the spendy side.
http://www.downandlocked.com/