Like it a lot. I've run almost this build myself and were pretty happy with it. Feel like 'Perfect Timing' really should be replaced with 'Magical Footwear' since Kalista really don't need the Stopwatch compared to the 10%-extra-boots. Perhaps also focusing a slightly bit more on CD. I ran sorcery as my second rune path for the great ultimate reduction, but I do see the pros of running precision with the 30%+ AS. Fine guide - Hope it will get worked further on:)