Just go with your gut. You know when you see "the bike", "the one". You just know it is the one for you. It sounds like you have done all the research. Just buy the one that you think is for you. Don't make this harder than it is.
I'd recommend the Nikon. I am a Nikon photographer and besides Nikon Rules!
;)
Let us know!
Brian
Nikon Samuari #2!
Ride On!