I made a quick video to compare some writing/drawing apps on the iPad Pro. I used the built-in Notes app, OneNote (which has been my note-taking app of choice to date) and Notability. I measured how long it took for the ink to catch up to where the Pencil tip was at a given point, while drawing lines at the same speed. I guess unsurprisingly, Apple’s Notes app had the shortest lag at 33ms.1 Notability was slowest for me, at 112ms, and OneNote was in the middle at 87ms. While I’m starting to like Notability enough to use it as my primary notes app, I can definitely perceive its increased latency compared to Notes. It’s responsive enough not to be a problem, but it just doesn’t feel quite as nice as Notes. Hopefully more apps will achieve lower latencies as they get updated.