Vincent Rebours

The Spirgrips are an immediate and obvious support when it comes to climbing up. You have a better position on your bike, you exploit perfectly your energy, and the grip on the handlebar is optimal. 
In downhill, it takes a bit more time to change habits. Then, when you get used to use the brakes, it is a great comfort. 
On flat roads, we detect that we do not ever grab the handlebar by its extremities anymore.