I have 2009 and 2010 Force, I like the 2010 force slightly better only because the front has trim. I have red cranks simply because the chainrings are stiffer and I like the look better. The Red cranks I got with the 2009 force group, purchased for an insanely low price from a friend who hated SRAM after a few months of use. So when I ordered my Madone, which I paid way less then $4500, I got 2010 force and swapped the crankset.

I really like SRAM, get what you can afford, is it "worth" the extra $$, only you can decide.