I haven't been able to figure out the reason for this: why is it that scrolling the map in Osmand is so janky?! It's ridiculous: scrolling stutters at ~5fps and when I let go it re-draws everything with no attempt at caching things or smoothing the rendering process. I've no idea why this is the case but it's definitely the only major blemish on an otherwise superb app.
I fully agree, Osmand is so close to being great. It's clear that a ton of work has been put into it, but has a few major flaws that make it nearly useless. It's the first open source project I've considered contributing to, and I might do it soon.
* The jank you mention - it was one of the first things I noticed as well.
* Search just doesn't work. They have addresses and POI in their database, but for whatever reason, search strings don't match, and addresses don't work at all either. It's completely broken.
* Really needs the ability to toggle direction mode, i.e. always pointing north, or pointing in the direction of travel or the device's compass.
I also would like to add a couple improvements that are not really flaws with the app:
* Ability to record GPS path
* Ability to share recordings/trails - would allow me to get rid of AllTrails
This largely rectified the address search in OSMAnd for me, though it does not update automatically and so requires occasional reapplication.
Hope that helps!