From the Wiki:
"Frost Shot: Ashe's basic attacks and abilities apply Frost Shot 2 Frost to affected enemies, slowing them by 10 - 20 (based on level)% for 2 seconds and causing subsequent basic attacks against them to deal 10% (+ 100% critical strike chance) AD bonus physical damage while they remain slowed.
Critical Slow: Ashe's Critical strike icon critical strikes deal no additional damage, but instead triple Frost Shot 2 Frost's slow strength to 30 - 60 (based on level)%, decaying over 1 second to its normal strength."
Given that critical strike items now take longer to build (their gold cost is increased) and that Infinity Edge costs a mountain of money, Ashe hitting her maximums on critical strike chance are much lower than they were before the marksman item updates. Because of this, Ashe, who's supposed to have utility that excels in the earlier stages of the game, is crippled by her itemization and her kiting is pretty much worthless until she gets a significant investment in items. At that point, her kiting is less important, because towards the middle and late game, kiting isn't as strong as it is in lane, especially with team fighting being more common.
