Unfortunately, Tracktion's overall nice design is completely ruined for me by having an unusable piano roll editor. Manual MIDI editing is really important when your keyboard playing skills aren't up to par (or when you're a kid and can't afford a MIDI keyboard).
FL Studio's piano roll has been out there for a decade, I just can't understand how other DAW vendors didn't match features with it yet.
This applies to the entire GUI tbh - that flat look is great for some things but there are plenty of places in a DAW where you need some kind of highlighting/shadowing to make small detail standout.
FL Studio's piano roll feels like Photoshop: draw some notes, select a couple with shift+click, make them shorter by dragging the first one's right edge, actually they're too quantized so do it again while pressing alt to not be limited to quantization, duplicate them a bunch of times with ctrl+drag (I think? It'sbeen years), then select the entire thing and duplicate it above twice to turn it into a series of major chords, select a few of the middle notes and drag them one row down to make the notes minor, then select all and right-click-drag the velocities to create a rise towards a crescendo (try that on a drum roll, sounds great). Or, my favorite flow: record some things, then select all with Ctrl+A and shrink it to 1/2 the length so it's in the speed I planned it to be in but can't play well enough to record in.
Tracktion's feels like a grid editor: you can edit specific notes but there's not really any useful keyboard shortcuts or mouse behaviors to help you draw music with it.
FL Studio's piano roll has been out there for a decade, I just can't understand how other DAW vendors didn't match features with it yet.