Running dev preview 8.1 on my 520, everything works well in India, even Cortana gives directions to bars around, after the recent 8.1 update, battery life has been great, even Facebook beta for 8.1 has got the new look plus I find it better than it was on 8, also I'm enjoying time me Live tile app as well as files app (file explorer from MS) which were unavailable on wp8, and lastly, action centre as well all apps to SD have made my phone more useful & faster, even little features like automatic app update, battery sense, swipe keyboard, seperate volume control, add value to your device.
As far as voiding warranty is concerned, nokia care (bangalore) repaired my power button (when 8.1 was installed) without any fuss about the dev preview that was running on my Lumia.
There are no downsides of having 8.1, & if you have access to Wi-Fi I would suggest switching to dev preview, anyways when cyan comes out it will be like a regular phone update
Sent from my RM-914_im_india_269 using Tapatalk
As far as voiding warranty is concerned, nokia care (bangalore) repaired my power button (when 8.1 was installed) without any fuss about the dev preview that was running on my Lumia.
There are no downsides of having 8.1, & if you have access to Wi-Fi I would suggest switching to dev preview, anyways when cyan comes out it will be like a regular phone update

Sent from my RM-914_im_india_269 using Tapatalk