Not strictly related to DietPi although I will be trying it out in due course - I received this today. The 32 GB MMC I bought for the XU4 works fine with it. It is mainly to run Kodi so given a recent post in this forum about DietPi and Kodi not working just now I opted for LibreELEC. Works well so far - I was almost caught out when it didn’t see the shared MySQL database but this was fixed by getting the device to wait for the network before booting. It plays 1080p x265 video with ease - files that an overclocked Pi3 couldn’t handle. For some reason some 720 x265 files play audio only - not sure why. Nice device - posted in Korea on Monday arrived in NZ Thursday.
Update - fixed the x265 problem with the help of this thread: