I'm a radiator and I love it. Great on hotter rides or under a jacket in the springfall. I heat up on cool rides with my wind jacket, especially when climbing. Love the chest vents for a breezy climb with just one half zip of the rain jacket. Good summer jersey on its own or in combo with a jacket.
I typically ride mornings so have yet to be in extreme heat.
In any case, overall fit and feel is great on this jersey. The rear pockets sit at the proper height to be able to reach back and retrieve stuff as needed. The arm bands feel a little stiff but they stay in place and I think are reflective.