Depends on how well equipped and how you have your attributes setup. If you are at least 200~300k power I would go with the Labyrinth, just keep in mind the higher the score the more exp you get, even if you fail you still get around 23k exp.

The reason I mention between 200~300k power is because the first boss you get on Lv 1 Easy Mode is around 150k power, the subsequent bosses if you get a score of 600 or more increase with power. I've made it to the second bonus boss in there and its power was around 340k.

When you consider a failure in the labyrinth against the amount of exp you would get in the wild depending on your level range you might actually get more exp in the wild if you can't beat the labyrinth.