Looks like I'm too late.

I'm a hair under 6', 32" jeans inseam (don't know my precise 'cycling inseam'), and I ride a 60cm CrossCheck. Until recently I had a 110 stem on it too, but as a fit test I've swapped it out for a 60 and it still feels ok. I also have a lot of spacers, so the stem is basically at the top of the uncut steerer.

I would have advised you towards the 58, but If the 56 is more comfortable for you, then more power to you.