I've used four of the Ramshot rifle powders for over 2 years now. Haven't noticed them being temperature sensitive, but then seldom gets below zero around here and I don't own a chronograph to note any velocity changes due to temp differences.
As noted earlier, found the Ramshot powders to burn clean. But, what I like about them is how they meter so well. Most of my reloading is done with Lee dippers and dippers I've made. Yea, I have a balance scale and a couple of digital scales, but seldom use them. Due to the fine spherical granules of Ramshot powders, I can throw a pretty consistent charge of powder with my dippers.