Best smartphone available in the UK in September/October

In September I will be visiting the UK for a couple of weeks and want to take advantage of being able to purchase an 'open' smartphone, so I am calling on your recommendations or suggestions on what to get/wait for.

I currently live in China and though I can get hold of HTC, Samsung and Apple phones they're priced similarly to the UK and, with the exception of Apple phones, they tend to run custom ROMs that don't support Google Play Store.

My phone at the moment is a HTC Evo 3D which I've generally been happy with, but I'm tempted to move away from the bloatware and skins manufacturers put on their devices in favour of a more pure experience, as found with the Nexus 4, HTC One Play Edition or Samsung Galaxy S4 Play Edition.

The key reason for upgrading from the Evo 3D is for a better camera. The camera isn't very good and because of the lag is takes a while to capture the moment. Anything other than a posed photo is difficult to take.

I'm not opposed to switching away from Android to a Blackberry, Windows or Apple phone so long as it fulfils the following criteria:

  • Can access the internet (WiFi and 3G; LTE is in the process of being rolled out in China and though would future proof the phone it's not crucial)
  • Good camera (not overly concerned with megapixel count but more the speed to take a photo and how good it is in low light)
  • A reasonable amount of storage (for apps, music and podcasts)
  • Good battery life (ideally that will see me through the whole day with casual web browsing - I don't tend to make many phone calls)
  • Update path (an understanding that the phone will be updated in the next couple of iterations of the OS)

From the rumour mill I gather that a new iPhone may be announced in early/mid September, so if you think I should hold off for that let me know. Also, if there are any other planned phone releases due out before the end of September/October I'd be interested to know what they are.

Cost is not an option however the phone must be available off-contract/SIM free and able to bring back to China with me in early October.