I hate over the bump stuff too- much prefer under. Another thing with mat clothes is that I detest them (all clothing actually) in non-natural fibres. A bit of elastane mixed in is okay but I just don't buy acrylic/polyester stuff as it feels yuk on the skin and is unhealthy. So I love cotton, linen, wool, hemp etc
Also, I don't expect to be wearing mat clothes long after baby is born- just until Ifit into my regular clothes.