Image quality almost always inferior to original prints of the same title, sound quality may be inferior as well. A 16mm print made from a negative which was made from a 35mm release print.
Quality is dependent on the source material and the lab doing the work.
It can range from worse than dupe to better than original. A print made from another print with no negative. Generally higher contrast than the original and of higher quality than a dupe. Sharpest most detailed image you can get on 16mm. Often contrasty, but better than straight reversals or dupes.