Definitely some pros and cons to doing it! I was doing my own travel around the US and then New York was my last stop so booked the tour because wanted to get some guidance of things to do because there is so much! And wanted to meet new people. The activities that they organise are great to do and a few options to choose from for the additional excursions for your day off.
The downside I found was that this 3 day tour is an add on to another top deck tour which i didn't realise. So, the group had all be travelling together for last few weeks on the west coast before coming to NY to finish (not all the group came, it was optional extra). Not that you don't make friends but harder to find your place for those few days of that makes sense?
Also, the tour technically finished on the morning of the third day so you do only really get one day of preplanned activities and then a free day then it's done. I found it worth it because I was spending the rest of the week in NY and a couple of people from the group also spent a few more days there so was able to do things together which was good!
If you do go NY you'll definitely want more time than what's on the tour. I had 6 or 7 days all up and I still didn't feel like I got to do it all haha
So if you can try give yourself more days to keep exploring the city!
This was my first topdeck experience and really enjoyed it so would definitely use them as a company again (if that's useful haha)
Hopefully that's helped a bit! Feel free to message me again if you want me to give you any other ideas on the different things you can do. Definitely would recommend going to NY though really is quite the experience!
P.S Sorry for the delayed response I tried responding to this in the email thing they sent me but it doesn't seem to have worked!