I've only done it with sorcerers (with no ML), but I found it really good, got to lvl 15 in about 40min. That was after killing the bosses in Newhaven and upgrading the wand. The loot is good and you cal sell it on the island which is a plus. As a mage, the good thing for me, comparing to other locations, is avoiding quick deaths caused by stronger monsters, as the island is pretty balanced for lower lvls.
The only other option I think its better is doing tasks for the paw and fur society, as you get xp for delivering and can start with crocodiles.