Taking tram 28 was good experience for me to discover the spirit of high steep hills of lisbon. It went through some attractions of old town and if you are lucky to take a seat in crowdy tram, then you can watch outside from your window and enjoy. The price ticket is very economical(1.4 euros) but keep in mind that you should take the ticket before you take the tram otherwise you will be charged more. It is better to take the tram on the first station(both sides) otherwise you probably will have unpleasent experience stucking between crowd in the tram. When I took the tram, it was also went through some shortcuts(or alternative path) because the original one was under some kind of construction and was temporarily off the service. Generally, considering the ticket price and friendly atmosphere of tram's inside, I recommend taking this tram. But even if you miss this during your trip to lisbon, do not worry much and instead, discover the city of seven hills by foot!