I've a number of VBR mp3s that will play just fine but will report as much longer than they actually are. Cog seems to assume they are all 32kbps and calculates from there. So trying to seek in these songs is a bit difficult. 
1 2008-07-12 18:36:26
Topic: Some VBR Mp3s reporting incorrect length (0 replies, posted in Bugs)
2 2008-02-01 11:05:22
Re: VG music files get cut off at 2:30 (6 replies, posted in Features)
It's difficult to say what's best. The songs meant to be short (like was said, level select music) start to grate your nerves after a while but then don't forget there are some ending songs that are non-looping and last 20+ minutes (like some of the Final Fantasy's). Hopefully it can be worked out to make this user selectable.