well the neo makes more power from factory so u dnt need to modify it as much to make round the 250 mark (more mods = more money and more stress on the engine) the neo engine runs solid lifters, gtr rods, larger ports, bigger turbo, variable valve timing, u can also fit a live board to the ecu so remaping is a breeze u only have to plug the laptop in, not re chip it.
and neo engines arent really that much dearer than 33 rb25s
dnt get me wrong the r33 rb25s are a awesome engine id just prefer the neo