Only a very small gap is there when Apex changes from NTSC track to PAL track and vice versa. CDs with ONLY segment tracks don't playback, or playback strangly or might skip tracks, etc. Annoying, but not a real bug. About MP3 playback MP3 playback is very clearly an addition that wasn't supposed to be in the player at all. At least the way how it is implemented leaves much to hope.
Sound is clear, ok.
It also plays all various range of MP3s, like VBR files, etc. One thing is controlling tracks. When you are already playing a track, you can't move around in the tracklistings to select the next track where you want to skip to - you have to stop the playback and select the next track then. Also, fast forward and rewind don't work in MP3 mode. About DVD playback DVD playback is very good overall - selections work rapidly, picture is clear and sounds are good.