Well from 1 to 10 you dont often, but 10 to 20 you can easily. 2 acc Invention enhancements in a power will cap you.
Having said that, I am one of those guys that actually turns off xp fairly often. For example, starting a new character in rogue.. you can stop your xp at 10 and do all 4 story quests for both factions. Stop it again at 14 and do all 4 of those and at 20 to complete the rogue isle chains. I like doing the arcs at the level they were ment to be instead of coming back with oro.
As you can see, with my playstyle, this change would benefit me greatly. Again in the end a QoL change but one I believe would be welcomed.