Thanks for all the comments guys.

I already had Choice Toy down on my list so good to know that is a place worth going.

Looks like I'll be heading to the largest Toys R Us I can find in Shanghai and hope their Transformers displays aren't as pathetic as the ones here in HK right now.

I can't find any other hobby toy stores (in English) so I guess I'll just take my chances as we wander around areas should we get the chance.

I head up to Shenzhen once in a while so I know how bad the fake market is unfortunately. I've had shopkeepers swear black and blue their fake stuff is officially licensed when it obviously isn't.
I'm a purist and don't collect KO or fake figures so I'm a bit of a stickler for double checking before I commit to a sale. I'm wary even in HK and always try and point out to others the stores to avoid or double check because they mix real with fake to confuse people. I entirely expect the same is true in China.