Hi Nicky
Go for it - you won't regret it!
This is a really popular tour - like Bob I did it in October 2014 (two weeks later than his departure). If you put 'China' in to the search function on the top right of the page, you'll find Bob's review and hints and tips from many others, including me. (and I genuinely do recommend the 'ear massage'!)
I understand that it's no longer possible to do the 'Panda Keeper Experience' (i.e. 1-2-1 Panda hugging) which I was fortunate to do at the Research Centre in Chengdu but you'll still get to see dozens of these amazing creatures (as well as some of the slightly bizarre looking Red Pandas) and, at that time of year, there should be lots of cubs in the nursery.
Happy to help if you have any questions but once again - go on, book it - you know you want to :)
All the best
Mandy