might check it out. the VATS system just felt like cheating to me oh pop up vats i win!! GGI found them all equally enjoyable in their own ways and in regards to the world size, do not care overly about the world size as long as I have a blast playing in it (which I did in all 3). Sure some elements have been streamlined and its an RPG lite, but most the key stuff that made FO3 / NV great is still there.
With that said, reason I suggested FO4 as I mentioned was the gunplay is much improved over FO3 / NV and OP mentioned they did not like the VATS system.
If you like open world action RPGs, try ELEX. It's from the makers of Gothic and Risen. It's rough around the edges, but it certainly has it's merits!