Varget is about 10 times less temp sensitive than RL-15 according to Hodgdon's tests.
While that is a big difference, it's not necessarily a problem for the average user.
In other words, temp sensitivity isn't an issue until it is.
When the military was looking to solve real problems with their existing long range designated marksman ammo caused by RL-15 under actual combat conditions, RL-15 was found to be much too temp sensitive to pass their tests and get the job done, and it wasn't a close call.
Shooting 100 yard groups at the range, probably not, but when the success of the mission is at stake and lives are hanging in the balance, then it matters.
