I have waxed lyrical about the Popcorn Hour range of players before, but they're all too large to carry on extended holiday or business trips. I went to go buy a Popcorn Hour A-400, and spotted the Popbox V8, a small media player which, upon testing, delivers very good video playback performance and relatively good stability in a small, compact package.
And the codec support / playback performance is as good / great as its bigger brothers. Small enough to travel with, will be testing it out in the field next week. I suspect it will do quite well.