Dragon quest 8 leveling up help? im level 27?

I am at the point where i just got the magic mirror and now I'm supposed to go find the guy who tells me how to recharge it (ive played through the game maybe 4 times in total, I'm just starting to play my ps2 again, its been maybe 1-3 years since I've played, i forget a lot about the game now.) And alot of people say to just stick with metal slimes, but from my experience with LMS and MKS from my other save files, they give a lot more EXP. as of now, MKS are not available for me yet, as i am not that far yet. i do have the ship and i can travel places, but I'm not sure if i should try to locate LMS of just metal slimes, so please tell me which one is better. and please tell me the most common area metal slimes appear at, and the most common area LMS appear at. (like the place they show up the most at.) I use to use the embankment near the riverside chapel but that isnt to helpful anymore. please answer detailed. thank you.