This has been asked in feature requests but with no comment made. I hope no one minds a repeat (my logic for restating is that some may not have trawled through all feature requests but may spot this if it's on its own).
I'm currently only using Cubasis for recording audio (vocals) but I understand that the problem also applies to MIDI.
The problem is this: when loop-recording, any and all previous takes are heard so, by the times you've done your third or fourth take (in my case, lead vocals), you're monitoring a choir. It's virtually impossible to clearly hear the vocal being recorded.
I can certainly understand how there may be a use for this method of monitoring (one may be improving a set of harmonies) but, to my way of thinking, we certainly need to be able to switch 'current take only'.