I never had big problem with it, maybe a reboot sometimes but nothing wrong.
I had also problem with screen when it was dirty or wet, it was not working properly but after cleaning it was okay!
I used it in shower or in swimming pool very often, and yes it's a waterproof mobile. I never had water problem with it.
It's still working today, and I think it's more reliable than a samsung or apple.
That's why I took an other blackview, my third one : the P6000.

I changed because I wanted to change for something more powerful.