I would say the most important thing is coverage in your area.
I switched from Verizon after 15 years for the 830, which I immediately regretted because the four 830s I had were all garbage - worst Lumias I've ever owned.
I travel all over the country, rural and metro, it's a simple fact that Verizon's signal covers more area. It's hasn't been an issue for me because the AT&T coverage in my home area is fine and when I travel I carry a company iPhone that is on Verizon with my personal phone set to forward calls to it when it's not in reach.
Now, for the 950. I love this phone, it's such a huge upgrade over the 830 and I've had zero issues or bugs with it. This phone has completely reversed the regret I felt for switching for the 830. So for me, yes, absolutely worth it but I can't say yes or no for you.