I would not recommend this to anyone. It's better to go and book the gondola ride from Venice directly which is much cheaper than from online. And back to my experience - I was traveling with my wife and kid. During booking, it was mentioned that we could travel with other people on the ride - that's fine. The other people were so huge and covered all space and one of us left sitting down. I requested the managing lady and she didn't help. I didn't argue with her because I was getting late for my train. So overall its waste of money.
I had to ride in a gondola just to have the experience of having done that in Venice. The ride was fine, though it seemed very short. Before my trip, I felt like I should prebook the gondola ride, but once in Venice, we saw lots and lots of gondolas that were just waiting to take tourists out so, it doesn't seem like having to prearrange a ride is necessary.
This was an enjoyable trip, but there was absolutely no touring from the gondoleer. I wasn't expecting a full blown tour by any means, but I figured that there would be something. The ride was calm and it was a beautiful day. If you go to Venice, you should definitely do a boat ride before leaving but I would suggest one that is more of a tour even if it isn't the fancy singing and musical ones.
We were 10 minutes late due to not knowing about the different Sunday service, so the man turned us away, even though I explained it was my mums birthday and our last day here. She had been planning going to Venice for 30 years to have this experience and we didn't have the money to pay again.!