I bought one earlier this year and tried it out in YNP. Bottom line……I really like this lens. I bought the older/cheaper version as I use it on a D90. You should not be disappointed. F4 seems to let in plenty of light and still gives some nice backgrounds. From F11 and up, its flippin’ awesome. At 12 to 14mm, you get a whole new perspective on things, a different way of seeing things. Good Luck & let us know how you make out.
Nicely done…..of course the economy wasn’t in the tank when I bought mine. I think you’ll really like it. I should have a few photos next week….headed to the Smokies Monday for a week.