I wear a size 32-33 waist, 32 inseam and ordered the Medium. I need the Large on this one. I just got the Medium and it's tight on the hips and a tiny bit short in the length. Would be fine if they were dress pants. I'm 6'1'' 175lbs. Haven't used the pants so I can't testify on the quality yet. They seem nice though.
I'm wearing the Medium size coat and as a regular raincoat I wouldn't want it any bigger. I guess thats common with Marmot sizing as I have the Medium Mainline jacket and the Large Randonnee Ski Pants for skiing/cold weather.