It seems to be that it's about time (sic) that Logic edits would be instantly audible. Something as simple as muting or soloing a track or region does not instantly produce the desired result. There is often a delay of seconds before the change is audible! Similarly for moving or editing regions and other edits. Why is this so? In other programs (to remain unmentioned) the results are instantly heard. This problem persists even if the Track Mute/Solo option is set to the misnomered "fast".