We've done both the round-trip commuter ferry ride from the wharf at ss Great Britain and the 45-minutes Bristol Packet Boat Trip with commentary from the wharf very nearby, and for a 70p less, the much richer experience is to be had on the ferry. 1) The view from the Bristol Packet boat was much more limited than from the ferry. At one end there is the toilet and at the other end there is the drinks & icecream bar, so you can't see ahead or behind, and the sides of the boat are high so you can barely see over when sitting. On the ferry you can see front, back and to the side and you get a much better sense of what is going on in the water. 2) You do get a bit of a commentary on the Bristol Packet trip but having spent a good deal of time in Bristol we can't believe how light-on the information was. We got more from chatting to the ticket-collector on the ordinary ferry than from the worn-out commentary on the Bristol Packet tour. 3) The commuter ferry that goes to Temple Meads station and up to the Cottage Inn shows you a whole lot more of the harbour than the Bristol Packet trip, for less cost. All in all, having done both, we'd definitely recommend an ordinary ferry ride over the Bristol Packet trip. That said, if it's important to you to have access to a toilet and to be able to buy an icecream or drink during your 45 minutes on board, take the Packet trip.