I use a lot of MIDI from Toontrack products. Drum beats, piano parts, ok only two things. I drag in an 8-bar drum beat I like into S1 v.4 and it's easy. But then, I want to change a fill or add a fill. So I drag a new fill to the last bar of the region and then they are overlaid! Now I have two MIDI parts playing simultaneously instead of replacing the original one with the new one. I can ALT+Drag to replace the ENTIRE region but then the original beat is deleted and then I just have a 1 bar fill. So now I have to undo my fill drag and drop, then highlight the last bar of the beat and press "DEL" to clear the region and make space for the fill. Great! I add the fill and it works. But wait, I don't like this fill, I prefer the original MIDI beat's fill. So I delete the new fill. Now I want to get the old fill back so I grab the end of the beat (now it's 7 bars long and I want to extend it back to 8) and drag it out, but wait, now it's blank! When I deleted the original fill, it destructively edited the MIDI file. Same with slicing a region. It's destructive editing.
I want to be able to delete, slice, copy&paste portions, all while still keeping all the information in the region. I want to be able to drag out from either end and retain everything like they do in Pro Tools. How am I suppose to easily audition different beats and fills? The only time it should be destructive is within the MIDI editor, but in the timeline, nothing should be destructive. If I'm missing something please let me know.