I think that the worst part of leveling up is from 49-55, due to the bad quests that are given on red and yellow map, so it is a good idea to work on TMQ4 for leveling up this faster.
Another possitive aspect of working on this Time Machine Quest is all the duels outside and the party making that was awesome on the old DBO, people meet each other and watch their progress, it was really fun.
Chill.