Organic Maps has a more simple approach and is more like Google Maps. OSMAnd~ has a much broader feature set.

I prefer Organic Maps honestly.

Organic maps ftw! It never disappointed me as a walker and is super convenient to use

Organic Maps have a much better rendering algorithm - meaning really fast, there is no lag when you scroll the map. OSMAnd has a really huge feature set. Almost anything you image from a map app. But it's soooo slow. I switched to Organic because I couldn't take the slowness.

Didn't know about Organic Maps! I always used OSMAnd for navigation.

Depends.

For simple routes Organic Maps is perfect. But if you want to plan complex route (like many waypoints, road avoidance), the OSMAnd+ is better.

Unfortunately both are tricky on complex highway exits.

I didn't use any for driving, but I can tell you that I switched to OrganicMaps from osmand+ for all other navigation. The main reasons are speed (OM feels a lost smoother and snappier), and functionality (it's minimal, but just works very well). I had no real use for all the bells and wistles of osmand+, so OM made sense for me.

I just downloaded both yesterday. Do these use the same maps/databases or what's the difference?

I noticed OM gives more detailed control about downloading smaller map bits.