We just came back from this tour and we loved it! The tour guide was very amusing with his commentary and I found it nice to learn things about the city's (Sydney) history that I typically don't get from other guides.
The Blue Mountains were beautiful, they do their best to get you to do the most in the short time you have (about an hour). If you're not a fan of hiking/nature-walking an hour is enough. If you are, I'd advise you skip this tour and take just the "Blue Mountains" tour or take the train to Katoomba railway station to spend some more time there.
Most of the trip is spent at Jenolan Caves, which are astoundingly beautiful. The tour of the caves lasts a good hour and a half, and they really give you a great history lesson while you're climbing those 900-something stairs.
One word of warning: those who are claustrophobic or find it difficult to breath in 'cave' conditions, I'd advise you NOT to go. There was a lady who turned back a few minutes into the tour because she was having trouble.
In the pond nearby the cave (the blue one) you may be lucky enough to see a platypus but there almost was not enough time to take a look around the area between lunch and the tour.
We are exhausted and happy by the end, and our tour guide treated us to a look-see at some wild kangaroos!
We think we may have picked the wrong trip for us. Although the Seine River Cruise was nice the bus tour was not that riveting. You drive around Concorde Square about four times, in traffic, and at the time we went the sun wasn't close to setting so not much was illuminated.
Despite this, everything was easy to understand, they did a great job accommodating all languages. All in all, recommended for older travellers but not so much for youth. It was an unnecessary expense in our eyes as we had walked the entire tour ourselves already without knowing it!