Reaper through a Focusrite Scarlett 18i20. Also will use the Zoom R24 as hardware recorder at times for recording 8 tracks at a time, even if it does not have midi because can pop out the SDHC card up to 32 GB and put in PC and import those tracks into Reaper and further edit.
The R24 also is really cool in that it also acts as a looper/sampler, meaning you can have 24 different already recorded tracks that while you are playing other instruments you can just push the button(s) in and out of these pre-recorded sounds/tracks and even record entirety in Reaper, providing you have armed tracks set-up properly for each.
This can be confounding because the A4 only gives one the SUM of 4 tracks on one pair of stereo outputs, so not so much editing there and places more emphasis on how having midi output would open up a lot more possibilities .