is the 950 a threat to the S7

Sales doesn't matter to me personally. Just knowing how much better my experience with the XL will be to people buying the more expensive S7 makes me smile.

Sales doesn't matter to you, but it does matter to developers all over the world! And what that means is that lesser apps choices for windows phones going forward. And when that happens, it will affect on your experiences on XL for sure because what's a smart phone without good apps?

Experiences is a very perspective thing. You are smiling at people who using S7, but I think they are laughing at WP users who are using such a dead platform.
 
The only serious competition for the S7 will be the iPhone and a couple of Chinese phones. If I compare the marketing efforts of Samsung and Microsoft here in South Africa I understand why Microsoft won't even come close to a couple of percent market share. They've completely missed the market and it's far too late to rectify it.
But I'm a stubborn guy and will stick with my L 830 because it does everything I need. At a quarter of the price of a S7 it's a no brainer for me.