4K on a 15" screen is just stupid. If there's no Dell available with a 1080p then I'd get the MSI
Also worth considering, Dell will likely have better support (and probably better warranty options) if that matters to you.
I didn't feel like starting another new thread, there's a major version update of the forum software that's available. It's nearly a complete redesign so not a simple maintenance release. Currently planning to do this sometime Friday afternoon or evening.