I updated firmware on my O!Play to 1.40N. It does play 1080p60 (as it did before) and the sound does not break up, but the video is somewhat slow-y and jerk-y, it seems that the player drops some frames. Watchable, but not perfect. 20 Mbit/s bitrate seems to help, but the original clips from the Panasonic camcorder are not played fluidly, they spike to 40 Mbit/s, although averate bitrate is about 22-27 Mbit/s. Switching to 720p60 or 1080i60 output does not seem to help. Using a fast HDD instead of SD card via an adapter does not seem to help. So, not the best player for 1080p60 playback.
On the plus side, the new firmware made some newer MKVs found elsewhere on the Net playable, I think they have 5 ReFrames.
Most clips I throw into this player are played fine. MKV, TS/MTS/M2TS, MP4, WMV, AVI containers. MPEG-2 and AVC encodings. Supports subtitles and language switching. Plays DVD ISO files. I wish it could play DV-AVI files. Also, it does not play FLV clips.