I have pretty much given up finishing songs on hardware. I tried to do whole tracks in one take on Rytm, which is possible for minimal techno and dub techno, and once made a whole track just on the Circuit. But in the end… I still am an ITB guy.
I now use each hardware piece on its own, for instance developing a drum loop on Rytm, then some arp on A4, setting up performance macros for later use. While I am on a train, I might do some chords using Grovebox app on the iPad.
Then I record everything, usually starting with the drums, into Ableton. I might record an evolving sequence on the A4 while modifying the timbre using the perf macros, or use the Rytms scenes to get some variations. After the audio parts have been recorded, I slice the recorded waves into loops and arrange them into scenes. While doing so, I balance the mix then on the main part and add delay, ambient reverb and distortion as needed. I usually eq low end from all parts except the kick and bass - something which can not easily be done on a pure hardware setup unless you have access to some high power mixer, which I do not have.
Finally, I record the whole track by selecting the prearranged scenes, possibly recording FX automations while the loops are running. A track usually consist of 7 such scenes, A buildup up to scene 4, then often some break, than the main loop with everything in it including the kitchen sink, then a breakdown. I mix into a compressor such that I have a mastering friendly wave with -23 LUFS loudness.
After that, all goes into audio and is pre-mastered using a small mastering chain (EQ->Compressor->Limiter) such that I have a -14 LUFS audio in the end.
At each step, there is enough room to improvise and play, so this does not feel constrained at all. On the other hand, I can do with just one piece of hardware while I am travelling (I do that a lot), and still use whatever I like together in the end.
