Four things worth mentioning that were not mentioned: One, deselected drums will still play and can still be controlled by the mixer. This lets you use up to the entire kit without so much screen clutter that you can't accurately add/remove beats. Two, one of the dynamics is ghost notes, which are perfect for creating dramatic transitions into accents, among other things. Using them in combination with the different strikes and dynamics can produce stunningly realistic sounding results. Three, the "export bar" option will also export however many bars are currently looped, so you can export a bar, the whole song, or a section of the song of any length.

Four is the best feature of all... If you tap and hold on the 'current bar' button, between the arrows for step forward and back, the song aranger pops up. There, you can group bars into sections and name the sections, like verse 1, chorus 3, break 2, intro, outro, etc. you can also copy, paste, re-arrange, or delete sections. If you need to, you can adjust the number of bars in a section at any point.

I just thought of a fifth feature worth mentioning. The time signature can change at any bar of the song. And a sixth... The grid can be adjusted down to 64ths (or maybe it's 128ths. I don't remember off the top of my head) independent of quantize, tempo, and time signature settings.