I have seen some great half sleeves on woman and I have seen terrible ones.
They can look elegant it depends on the content.
I have two quite large ones, a rearing unicorn and waterfall which is on my right shoulder blade and takes up about quarter of my back and the other is a forest warrior faerie who wraps around my left breast, her wing in on my boob and her feet are under...following her is faerie dust with the first initial of all my 7 kids (man that hurt on the ribs and the solar plexus)...I would like to eventually join them up around my ribs and back.
I am not game enough to get sleeves done but do think if done properly they can look great