I've never noticed that big a difference between the two in edge retention, honestly. I've always attributed it to both being left soft, but M2 has never particularly blown me away. For me, it falls into roughly the same category as D2, S30V, XHP, S35VN and similar steels. All of them hold an edge for long enough that I'm happy using them, but all fall well short of steels like M390, M4, S90V, S110V, etc. Given that, I'll take ease of maintenance over what I've always experienced as a relatively small difference in edge retention.