I think the choice would largely depend upon how complex the music you’e making is and how many instruments you want to control.
I’m using my octopus to control about half a dozen drum machines and about a fifteen midi synths/effects. I think it would still be possible on a nemo but it would probably be too much like hard work.
If you only make tracks with a handful of parts you’ll probably get away with the nemo. If you’re greedy like me get an octopus!