I've been running an ODROID-U2 for three years[1] now, and can't say I've had any real problems - still running Ubuntu 14.04 wonderfully. What was the model you got?
The one that stands out is the OpenCV library that never materialized. Another was video drivers. Best approach is to be your own judge and go look at their support forum.
[1]: http://taoofmac.com/space/blog/2013/02/10/1230