On the face of it, when I first saw one I thought they looked quite good, nice and fancy and different from the usual box.
But I think when I see them in the shop, that the curve of the front tends to distort the image a bit, and looks to me a bit like your looking at the tank through a 'fish eye' lens. So although I like the style and appearance of the bow front, I wouldn't have one, as I prefer the clearer image you get of the tank contents with a flat front aqauarium.
But hey, each to their own, thats just my 2p worth!