I have a 707 and never noticed it running hot. It has never shut down. I ran snell type e-3 mains until a few months ago. Now I am pushing the w22 in walls with surrounds all the time.
It runs warm to med warm, but never hot.
Of course I run the surrounds and centres as small. Maybe that has something to do with it?
The Snells were always very easy to drive.