Reportedly this demo was done solely with the Rytm. I guess there are several tracks used with samples for the pad-sounds. As samples can be played chromatically or parameter-locked (e.g. different samples for one track) making such an arrangement could be done with ease.

One thought is how you prefer to work with and manage samples. If it’s good enough for you to manage a decent set of samples via a computer and you don’t need any sampling and editing capabilities on the machine itself the Rytm could be sufficient. If you want to dig deeper and bend and twist your samples as well as work a lot with drum loops or in general with sample loops, or real-time sampling the OT is definitely the way to go.