The value, if able to use it correctly, would be an excellent buy. However, on the day we tried to access the Hop-On Hop-Off Bus, we didn't arrive in Porto until 11:00am. Very difficult to find the correct point to pick up the ticket there are several in the plaza, but only ONE for the yellow bus. When we find the correct one, the operator tells us that we need a print-out with an OCR scan even though the directions say that we can use our printout or even the phone ticket Viator App. We spend nearly 2 hours trying to find an internet cafe, only to find that nothing we can print has an OCR scan. We return to the pick-up point only to find it closed for the lunch/siesta break even though the listing on Viator and our ticketssays it is open continuously. So we wait for another two hours until it reopens. After speaking with a different person this time, she accepts our printouts without an OCR scan. As our visit is only for the day and it's now 3:30pm, we decide to do the Guindais Funicular, which is not simple to find among the labyrinth of streets and alleys. Upon finding it, we discover it is closed for repairs, which we were not told when we picked up the tickets. It's now nearly 4:30pm, so we take the yellow bus tour which has a recorded tour narration through ear-pieces, but you can't raise the volume enough to hear most of it. The scenery was wonderful, but not knowing what we were seeing was disappointing. So basically all we got for our money was one loop of the bus tour which we couldn't hear, a short ride on a trolley which was fun, but not knowing anything no narration uninspiring, and a short ride on the tram which was full of locals who would shove on and off with no regard for kindness and the driver who left us off at the wrong stop so we had to walk half a mile back to pick up the bus. And nearly 5 hours of wasted time wandering around trying to get the right tickets which we had all along, waiting for the siesta to end, and finding a closed funicular. Porto has its pretty spots, but this process, especially with proper directions either on this website and/or tickets, better trained employees at the pick-up point, and working volume on the tours, mainly just made this a stressful and tiring day.