I recently put two sets of these on my home 45 deg wall. As a red river gorge climber, I need to be able to pull steep pockets. In "The Red," often pockets don't come just one at a time. You might have endless pockets to choose from for 20 feet. How and where you climb might influence what type of plastic pocket you want. Other manufacturers make pure, single pockets. You can tell from looking at the picture that these pockets are more complex. Holding them can be more representative of what one encounters when many pockets are next to each other. Are you just slipping your fingers in a slot, or are you pinching the space in between two pockets? Pure single pockets vs pinching multiple pockets requires difference technique. If your area has only a single pocket here and there, you might be served best by single pocket plastic holds. If you want to practice the more complex shapes one might encounter at The Red, you could do worse than these holds.
Finally, note that the difficulty of each Atomik pocket can change with the setting. Some of these pockets are very positive from one direction, but rotate 180 degrees, and they're brutally sloping. I like that ability to control the difficulty level, and get more bang from each hold buck, but other folks might like the simplicity of other company's designs.
My hands are average sized for a 6' male. Two fingers in each pocket isn't a problem. Three fingers can be a challenge, depending on the move. Typically I climb them two fingers at a time.