4 is better than V because it's not bland.
Nocturne did 'le walk around desert' good, V didn't. V has good gameplay, good music but everything else is bland. It's not even bad, just dull.
And I am talking about both V and Vengeance here, though admittedly V:V is a much more improved product, still bland though. Maybe it's a personal thing but it lacked everything that I found interesting about SMT, the sci-fi fused with eseoterical bullshit and magic. I want to see the fucked up society, the factions like the Gaians or Messians, all that interesting shit I can learn about the world. I, II and IV peaked for me in that aspect, out of mainline, much like Strange Journey did.