The Clipper fleet is absolutely one of the best parts about living in Pittsburgh. I love seeing and learning about my city, and seeing my city from the river is about as unique as sightseeing can get.
I have no (majorly) bad memories when it comes to the rides and events I've had and attended while one of the Gateway Clipper boats. Even the weather has always been good when I get on board a Clipper boat. Anything you could possibly want to do while on a boat, this fleet offers as a special event, including but not limited to children's events, dinners, fall foliage sightseeing, absolutely fascinating historical sightseeing tours, dance parties and 4th of July firework shows. If you do want to attend a special event, always buy tickets in advance; the Clipper fleet is extremely popular among locals and tourists alike.
Here are the drawbacks: food and drink will cost you a pretty penny. In fact, you're better off eating before you get on board (fortunately, Station Square offers plenty of options, so this won't be a problem). And unfortunately, smoking is allowed on the decks of these boats. A friend and I actually ended up moving to a lower deck because someone behind us lit an extremely disgusting-smelling cigar. It absolutely ruined part of the evening as we looked for new seats on a very crowded boat. If we had not found new seats I'm sure we both would have soon become sick to our stomachs.
Still, definitely fun, definitely worth the price of admission for the overall experience.