I gave these shirts four stars because they suit my purpose.  They are not high quality and the fabric is very thin.  But I was looking for a thin stretchy shirt to wear under sweaters without adding bulk, and didn't want to spend a lot of money.  And, YES, order a size up; they are ridiculously small.  I wanted a tight shirt, but if I hadn't read the reviews and ordered my usual medium, I don't think I could have breathed in them.  The large fits me the way I'd expect a stretchy almost-skin-tight medium would, so it works out.  The colors are actually really great.  Some are not quite as they appeared on my screen, but they still work for me.