I've had midnight blue leather since the 19th and it looks the same as it did then. I haven't set it in any water though. If I had I'd be worried that the phone would get wet. For example, I have an fitbit flex (polymer case) that gets wet sometimes so I always take the fitibit itself out and dry it off immediately. I'm really, really careful with my electronics though.
I do think the case will probably get some scuffs or minor scratches though because it's relatively smooth leather. I guess we'll see.
If I get leather shoes really wet so that they're soaked through, they're never really the same again after they dry but what can you do, right? Sometimes getting wet in unavoidable.