Get a new Korg ARP Odyssey. Put it through the paces, and if it doesn't suit you, then return it within a few weeks for a full refund. It won't be a huge financial burden one way or another.
The sequencer is one thing. But as for effects, I think there is an advantage in having to provide them externally in that you can choose from a much greater variety then you would have had onboard, and this can lead to a greater range of sound. Onboard effects are a matter of convenience, and sometimes that's important. But offboard effects are a matter of originality and flexibility.