Those are two orthogonal things, but they do both point towards Valve being the better choice between the two. But if there were a Valve vs. Microsoft duality where the choice that's better for anyone that's not the two of them is to side with Microsoft, I'd be disappointed with Valve, but I'd choose the Microsoft route.

I don't think that's likely, as Valve have repeatedly made choices that are better for the consumer even when they're not better for Valve, but I'm not ruling out the possibility.