I also found that Wondamobile sells the Hong-Kong 'Global' version with 6510mh battery. I asked them as below:
What's the difference between HK Global vs EU Global ? I see HK battery is better but what about google services ? Any potential compatibility issues with western software for the HK - Global one ?
Their reply:
Battery is better on HK Global version. All others are the same.
Seems like the 'Global' HK version will be the way to go if you want the bigger battery but won't be able to know whether there are no issues with western-software until someone gets it.