Yeah, I had a feeling it would be easy-tier. Only had a few attempts and already easily reaching stage 5. That's coming from a recent Deathsmiles II clear, which I felt was noticeably more challenging than the original Deathsmiles, so I think your ranking is going to roughly align with how I perceive difficulty across the games.
Also, when I mentioned port modes, I meant all port modes from all ports, not just DFK. Also, I notice that Akai Katana and SaiDaiOuJou are missing from the list, presumably they hadn't yet been released when this topic was started. Where do they fit-in?