Hi Alexa
I did this tour in 2014. If you put 'China' into the search function at the top right of the page, you'll find a number of reviews, including one from Bob Gray. It's a super, full on tour with lots to see and photograph.
My tips would be to take plenty of wet wipes and tissues plus throat sweets and cold/flu tablets as the pollution gets in the back of your throat (most of my group went down with a cough or sore throat by the end of the trip).
The only downside for you is that I believe that they no longer offer the 'Panda Keeper Experience' (i.e. Panda hugging) at the Chengdu Panda Research Centre. I got the chance to do it and it was truly life affirming - something that I will remember for ever. But don't worry, you will still get to see dozens of these amazing creatures (and their weird cousins, the red pandas!)
In terms of spending money, as all meals and transport are covered, it's really down to personal souvenir shopping habits. The main tourist sites, including the silk and jade factories, will take credit cards but you will probably want to take some Yuan with you. You will find the shop assistants in touristy stores quite unnerving. They will follow you around a shop, usually invading your breathing space, if you show the slightest interest in anything. I'm not sure if it is because they are on commission and desperate for a sale or just trying to deter shoplifters! You will also be mobbed by street vendors every time you get off the bus, all shouting "Hello, hello Missus" while attempting to sell you a 'genuine' Rolex for ten dollars! It's all part of the fun of the trip.
As for the weather - my trip was in early October and surprisingly chilly. This was down to the cloud/pollution cover, especially in Beijing and Xian. However, Bob's tour was a month before mine in September and he reported super weather. I think it's down to luck and whether they are expecting any visiting Royalty or Diplomats. When this happens, they shut down all of the factories for a month in advance to clear the air but then after a visit they re-open them and go on 24 hour production, hence the smog! I would take layers and at least one fleece and a light rain jacket to be on the safe side. Don't take an umbrella because it will be confiscated at the Forbidden City, if not at the airport.
Have an amazing time - happy to help if you have any other questions once you've read the reviews.
All the best
Mandy