They are a hair too loose, but very comfortable.  I wouldn't size down.  Based on reviews and size chart I went with a large.  I normally wear medium or sometimes small depending on the brand.  My hips are 39" and my waist is 27".  I'm 5'6" and 140lbs with a somewhat athletic build.  They're cheeky without being overboard.  I wash mine in a delicates bag.