I am sorry for the delay in replying.... Actually busy in Diwali celebrations.
I actually do not have a usb pen drive greater than 4gb, I shall buy a 16 gb usb very soon and post the details. But I am sure it should play.
Regarding .m2ts, it does not support this format, but you can always use a converter to convert it to mkv and play.
I am listing below the file formats it supports that I have tested.
VIDEOS: .avi, .mkv, .wmv, .mp4, .mpg, .mpeg, Handycam dvd recordings(AVCHD).
AUDIO: .mp3, .wma, 2 channel AAC encoding, 5.1 channel ac3 encodings, 5.1 channel dts encodings.
As, this player does not support 5.1 channel AAC audio encodings, I am converting them to 5.1 channel AC3 audio encoding in a mkv container and enjoying them in my onkyo receiver. The end result is great and the sound effects are mind blowing. My receiver's Dolby Digital 5.1 indicator lites up correctly. And all the conversion just takes 10-15 minutes of time as the video part is copied.
I shall confirm on > 4gb playback of .mp4, .avi, .mkv in NTFS format after Diwali.
Thanks,