I would look at Ardor3D and have another look at JMonkeyEngine.
Created by the original JMonkeyEngine developer(s) who decided a clean break was required so they could start over and use all the experience gained to create a better API and platform.
The people I know who have used Ardor3D have very positive things to say about its design and API. It is actively maintained and has a good community and good API documentation, although tutorials are a little short in supply and generally you’ll have to be familiar with 3D programming concepts to be able to pick it up.
A community-led rewrite of JMonkeyEngine 2, driven by dissatisfaction with JME2 design and related issues caused by said design, it has gone from strength to strength since its release.
There is ample documentation including tutorials and plenty of projects using it. If you had issues with JMonkeyEngine 2 or earlier, it is well worth another look at version 3.