OK back from holiday, it worked pretty well, all my stuff is encoded to MP4 and I'm pretty sure that you won't be able to playback an MKV stored on the Seagate through the iPad.
It does seem to struggle with 1080p files, especially if there are subtitles, I can only think that the wireless is struggling to keep up with high bitrate 1080p files.
I can't see why it wouldn't work with mirroring the iPad to the ATV, I can give it a try, I used the Digital-av-adapter and that worked really well. Transferring films across was pretty speedy with the USB3 interface.
One thing I did notice is that if you use the Seagate App it won't let you fullscreen the video, ends up in a stupid box in the middle of the screen. Luckily I tried accessing it with Safari through the HTTP interfaces and this worked like a dream, allowed you to go full screen.
Another nice feature is that you can actually add the Wireless Plus to your own wireless network, it picks up a DHCP address if give your wireless SSID and password. It still also seems to be available via it's own private wireless network as well which was unexpected!
If I had bought it a bit before the holiday and had more "tinkering" time I'm sure I could have ironed out the issues I encountered
Let me know if you want me to try out any other tests, glad to give it a try (time permitting).
