I have searched for a light, full-length nightie that is neither cotton nor sheer lingerie for years, and these Shadowline gowns are PERFECT!!!  I got one in a blue that is one size too large, and then I got this in medium and it is PERFECT!!!  It is light, soft, comfortable, easy to wash, the right length, the right weight, the right neck...can you tell I like it?  I would say the sizing is very accurate and the first one that is a little too big is my mistake (and it's still OK, just a little too long).