That's why I'm now using Unreal Engine 4. If you're comfortable with C++, I'd recommend it, though it's still more or less in beta at the moment.
For instance, my game builds are ridiculously large, because you can't store your textures in a losslessly compressed format (you can load from URL a png manually, but then you have to manually apply them to your models).
Unity has been so successful because it's been an "OK" tool in a land of rubbish. It seems as though it's finally getting some strong competition at a comparable price point, which is great for everyone.
Either Unity will step its game up (which I'd love, I don't want to switch tools), or it'll enter a long, slow period of decline.
I'm not sure if the new "png" format would work for 3d textures though- there might be some other weirdness there (like maybe you can't turn on mipmaps or something) since it's supposed to be used for 2d sprites.
So, what gives? What is the nature of the mono problem and who is responsible?
And the relation between Xamarin and Unity seems bad : http://gyazo.com/ecdf4d7e732ec876b4de9ddf95fdedca