[@Feisty-Pants]

Depends strongly in the ability. Someone with level 4 might be able to beat someone with level 5 just because of what ability they have. For example, an offensive level 4 like Noboyuki with his implosions could beat a level 5 that uses, say, sound? It also depends strongly in the person too, so people might get into interesting fight in the long run. 

In processing power, though, Level 5 are definitely superior than level 4, hence why they control their abilites a bit better, though level 4's already have pretty good control themselves. 

Well, that's my two cents on it nano desu!