The most annoying thing about this tour was the tour guide. When we started the tour in the morning the tour guide introduced himself and then started saying how the 'service industry' in US is paid less wages and the staffs rely on tips. (Please note that gratuity is optional for the tour).
And then when we got into this tour bus, there was a note stuck inside the bus saying that $8-$10 as gratuity was expected from the tourists. From there on the we were anxious and very annoyed as to why the tips are kind of demanded in this way. Finally when the first part of the tour was over, the tour guide was waiting near the bus door and waiting for us to give him the tips. We were as though forced to give the tips and then he started complaining 'is he only worth that much'. Some responsible person at Viator must make sure that when it says 'gratuties are optional' , the staffs should stick by the rules and not annoy the tourists.

This tour was great and the pilot was excellent. He was considerate and never expected any tips. Good on him.

We had booked this HOHO tour for 2 days. The first day when we presented the voucher to the tour driver,he gave us a ticket and nowhere in the ticket was mentioned that it was for 2 days of HOHO tour. So I asked the tour driver about this and he was so impatient and said something like that he his not going to fraud us or runaway with our money. If it was clearly mentioned in the ticket that the tour was valid for 2 days then I would not have asked the tour driver about this and so I ended up receiving sarcastic remarks from the tour driver. From there on he was like very unfriendly to us.
But the other tour drivers and guides were really good.

This was great tour and the tour drivers were helpful and pleasant.

This was the best tour of all the tour we did through out US. Firstly nobody insisted on giving them tips (tipping sucks) and secondly it was well more than money's worth.