Percent xp is better in my opinion... Seeing the amount of xp needed at level 209-210 is probably nothing I would like to see.
You want % look at the bar u have, each red bar is 10% and each yellow bar is 1%, there u go, too easy
Actually it's hard to judge exactly, is it .7 of a red bar or .8? To help fix this i took a piece of paper, made two marks the width of a bar, then created it so there were 9 more evenly spaced ticks. Effectively a xp ruler.
With that trick you can easily measure how much xp you have.
You could screenshot it and put it into a editor and count pixels but that tends to be too much work.
Also after doing a few more lix i did have an unusual bump in xp so its possible its graphical. I keep accurate records so it's not my imagination that there was some kind of change.