Going by what's being said, the game looks like a significant improvement over FO3 mechanics wise, but apparently the main story is as lacklustre as one might expect given Bethesda's track record.
Though I am tempted, I think for me this is one best left for a GOTY bundle once the inevitable bugs have been fixed, the equally inevitable DLC has been released and the modders have gone to work.
Though I am tempted, I think for me this is one best left for a GOTY bundle once the inevitable bugs have been fixed, the equally inevitable DLC has been released and the modders have gone to work.