Geist Sampler is a great tool to bring some of the live feel back to the grid / stepwrite recording process. I would recommend using and abusing this sampler as much as possible. After I crafted my arrangement in song mode, I recorded live drums, percussion and beatbox with the sampler feature. Geist then allows you chop up and slice your recording back into your 16-step matrix. This is awe-inspiring, as you can now sample your own playing on the grid and manipulate these 16 pads with maximum flexibility and control. Note: Pay close attention when exporting your recorded sample. You may accidently export your sample onto pads (already containing voices).
I did this several times, without realizing that you need to free up the pad space before exporting your sample. Otherwise, it will overwrite onto your existing sound.