All in all, I'm delighted with what the Mini can pull off and this post is to share info about my experiences and certainly not to complain. Some 720p videos will work for me and some will not
Yes, the glitches in CorePlayer I've come across many times, which I think might be caused by the profile the h264 is encoded with - that's why it's good to have a number of playback options.
I've found for example, the newer MPlayer that @Lastic bundles with SMTube is better at playing glitchy videos than older versions.