This is what Ender currently has on his site.
ExpMod
1.30 - level 1-35
1.10 - level 36-80
1.08 - level 81-150
1.05 - level 151-180
1.03 - level 181+
I suggest a change to something like this
ExpMod
1.15 - level 1-10
1.25 - level 11-35
1.18 - level 36-55
1.11 - level 56-80
1.09 - level 81-130
1.07 - level 131-160
1.05 - level 161-180
1.03 - level 181-275
1.02 - level 276+
I think this will help people who haven't played level up quicker in the very early stages hopfully making them want to continue to play more. :)
Then a change later on to help balance out leveling at much later stages once you reach lvl 135 or 140.