I've sent it back for a replacement - dust under the screen! when the device arrived I had a single speck under top right - figured no worries just got in there during manufacture..... However after just 7 days use I had huge dust clusters covering large areas of the screen (most noticeable when the screen is turned off).
I dont think this is a big issue for the device in general, I guess I just got unlucky. However spending £450-00 on a high-end smart phone, I want it dust free thanks!
Doubt I will see the replacement until the new year