Migration Assistant worked just fine for me, when I moved to my shiny new 27" iMac a few days ago (it's beautiful). I used an ethernet cable to connect and it was from one Snow Leopard to another.
I have very few third party apps - I would guess that if it's going to go bad anywhere, there it would be. Otherwise, a perfect transition, but then it's a mac experience.
Did I mention that I have a shiny new 27" iMac and it's beautiful? I'm stroking it now.