I am not an owner of the Atlas nor have I heard the Ikko OH10's, but I do remember from trying the Atlas' at Can Jam London last year absolutely loving them, I spent what felt like hours listening to them over the 2 days. If I had the funds I would have been an owner by now
You could consider IMR IEM's as a cheaper alternative, I was keen on the Atlas but not the price, but it had been brought to my attention that IMR acoustics and the IMR R1.
At the time I looked the newly released R2 Aten were available, it had good all around sound and staging, those and the R2 Reds fulfil my need for bass.