I prefer a more flat profile. But it's definitely a individual thing. Some are more comfortable on saddles with a rise in the back others aren't. Some can do either.

If the rails are level, that is probably how the maker imagined it for most of it's users. At least the saddles I've had seem to appear that way. But you can certainly go either way that suits you. Just try and see what works.

I wouldn't get another saddle till you ride this and figure out that it won't work for you. Don't change it because you can't figure out what level should look like with it.