Also, ART (the new vm introduced in Lollipop) was still pretty rough in Lollipop. IIRC it even has some memory leaks ... It is MUCH better in Marshmallow, so

Also, ART (the new vm introduced in Lollipop) was still pretty rough in Lollipop. IIRC it even has some memory leaks ... It is MUCH better in Marshmallow, so it is definitely worth upgrading because that's another thing where you just need to update the system.