I have both and i am thinking about selling the Octa though im still not sure the Rytm can totally replace the Octa for me so i will probably keep it.

Wish it was possible to transfer samples on the Rytm without using C6.
Its slow and feel like 1990 again.

Sampling on the Octa is great and simple but sometime i think its a little overkill for me need. I use the Rytm for drum and percus so the Octa is mostly used in live situation where i dont want to bring everything on stage.

In the studio i dont see any use for the Octa because i dont mind using the computer with my external gears.

So Octa minus :
-I never use timestretching .
-The Octa FX are so so compared to their other machines, something i dont understand because the Octa would really benefit from good FX.
-File management … not so great.

Octa +
Can be used as a backing track machine (streaming from card)
Sampling on the fly is great.
Great sequencer.

There is Strom that can be used with the Rytm but im not sure about support in the future and i use the computer most of the time anyway cause with the ipad i need a sound card to sample external gears etc.