Ok, thanks for the reply. There is not such difference in DOS so I think it was a bug. Especially because the gap is always in the same direction.

Even the custom character get some personal quests? Because the other player and I have picked two custom with no special background. For example, do the Champion quest in the basement (I don't know if it is the official name) give XP rewards only for the winner?

Originally Posted by Raze
Regardless, this issue is on the feedback list, particularly with co-op playthroughs where one person does most of the talking.

It's a good news. It would be a shame if we have to decide who does the talking because of XP rewards and not because of roleplaying matter.