D&D 4E 4E with no 1/2 levels bonuses

[Starfox]

the major downside is that it would be incredibly annoying to nerf down all the stats of monsters in the MM to compensate for the loss.

Not very hard to just reduce all the values by 1/2 levels. I don't feel I'd need new statblocks or anything to do that, I can do it in my head.