I'm a relative newbie to all Elektron gear. I bought an Octatrack last year and have been going through the paces patiently. I also bought a Digitakt, initially with a view to seeing if I should sell the OT.
In the end, the DT has helped me appreciate the OT more. They are both great machines, but the DT is more immediate. Now when I go back to the OT, I find myself replicating things I did on the DT that I perhaps wouldn't have thought of doing before on the OT.
So the machines are very complementary for me. Each to their own needs, and so on. Having experienced both boxes, and having the luxury to afford to keep both, I think it's too reductive to pose questions like OT v. DT. They're different, but both could easily find their way into the same setup, even in more experienced hands than my own.