For the athlete that is climbing in the V5 range, this is a set of crimps that you can run laps on when set on a 20-degree wall. They are easier than Set #2. There is a slight difference between Set #1 and #2 in that Set #1 is a little deeper at 1/2" and there is a 25-degree incut. You can expect V1- on a 20-degree wall.
On a vertical wall, anything more positive than this set would be considered an edge. This is an excellent set to throw on any beginner wall where the climbers intend to put in the time to become stronger. The incut is comfortable on vertical while they become even more comfortable as the wall gets steeper.
On a 45-degree wall, the incut is now sloping by 20-degrees. The difficulty feels in the V8+ range. The lip on the crimps is still present on a 45-degree wall which is helpful to stay on.
The next step in easier crimps would be the Golfus Steep Wall Crimps.
Set #1 is easier than Set #2, Set #3, and Set #4.
On a vertical wall, expect V0+ feeling crimps.
On a 20-degree wall, expect V1- feeling crimps.
On a 45-degree wall, expect V8+ feeling crimps.