Leaving the "lag does exist or not" issue aside, Google is working on a Dalvkit replacment called ART (http://source.android.com/devices/tech/dalvik/art.html ht

Leaving the "lag does exist or not" issue aside, Google is working on a Dalvkit replacment called ART (http://source.android.com/devices/tech/dalvik/art.html http://source.android.com/devices/tech/dalvik/art.html). KitKat ship with an experimental version of ART, and it seems to perform better in synthetic benchmarks than Dalvkit. People online are also reporting a smoother experience with it (but it might be placebo, I don't think there's a scientific and unbiased comparative between the two yet).