SE, just take off the level cap, it's ridiculous anyways... what people don't like out of anything is restrictions.

If the level cap is lifted, the experience needed for the next level is always adjusted and that's cool seeing that its done all the time and the exp curb is astronomically impossible to break. People would be grinding for days to get to lv.51 causing the fatigue to kick in, resulting in 10~0xp every kill up until tally.