We really liked the Duquesne Incline and found that it provided a wonderful view of Pittsburgh. You can't beat the price, either. We Chicagoans would definitely come back again.
I wish that I could give it 3.5 stars instead of 4, because the station does not have a bathroom. Two of my four children had to go really badly, even after we went before traveling. There's no signage regarding lack of bathrooms. They do have a port-a-potty at the bottom of the incline, back behind the station building, in a gravel lot. Would have been great to know that there is not potty at the top (which is what we were banking on when we went up) and there's only a port-a-potty at the bottom (in a very scary area).
We ended up cutting our time at the top short as we frantically looked for a place to pee.