I don’t have experience with the Roland MC line, but I do have some experience searching for that elusive “perfect” portable music making device. This post will be a little long and not DIRECTLY related to your comparison, but maybe it will be worth reading anyway as it does relate to your portable search.
My problem with that search for a more full featured portable device is that once I discovered the joys of the Elektron sequencer, everything else felt like swimming through molasses.
At one point, I had an MPC Live, and thought that I was “done” in terms of a box that would “do it all”.
But I decided to try a Digitone to see what all the Elektron fuss was about. That was it. Once hooked on the Elektron sequencer (and the sounds from the DN are indeed lovely), I started resenting any time spent on the MPC.
Also, despite the MPC’s depth, I found myself starting to rely on loops/samples, since the full MIDI sequencing workflows were becoming tedious and annoying, and falling back to punching in and out loops and samples on the MPC was not where I wanted to be with my music.
So, strategically, I picked up a Digitakt to mate with my Digitone. This gave me a sample-based box with almost identical sequencing workflows (no learning curve) and it was also NOT really a “loop player”, so the Digitakt encouraged me to use samples creatively and I could mix and match between the Digitakt and Digitone in sounds and sequencing.
Side note, I was into OTB hardware specifically for live performance, so I never really used the MPC to create full songs for passive playback, and therefore, lack of an arranger on the Digi boxes was not an issue.
Shortly (the day I received the DT), I was creating “full” sounding music with the DT/DN pair, and immediately sold the MPC Live.
My enjoyment of the DT/DN pair did not fade over the next couple of years or so, but I kept looking longingly at the AR and the A4, mainly for the idea of analog sounds with an Elektron sequencer to “complete” my setup. If only Elektron had a product that packaged some real analog fun in a Digi-type package to mate with my current DT/DN setup.
So yes, Syntakt was pretty much an insta-buy for me, and has now become my default “song starter” for the time being.
But having analog, digital machines, dedicated hybrid FM synthesis, sampling and more in three mated boxes absolutely scratches 99% of my OTB musical itches.
In terms of portability, I have discovered I’m not much of an on the train or in the park music maker. It’s only when I’m away from home or the studio for more extended periods (like vacations) that I want a music device with me, and in those cases, it will involve a hotel room with perfectly good outlets.
In those cases, I pick one or more of my Elektrons to take and even with just one box, I always have enough capability on hand to get down solid ideas when inspiration strikes.
This has been my personal journey in settling on my ideal little hardware setup, and unfortunately, I discovered that for me there was no “one box to rule them all”. The three “Digi” boxes are the best compromise for me, and in some ways, having three boxes each with more focused sound generation is a plus.
I don’t know if ANY of this helps or only adds noise to your thinking, but I hope it’s the former, and I wish you every success in finding that streamlined OTB solution that works for you.