I like the 7.62x25 better, more ammo is available right now from various manufacturers as well. Its not what I carry for self defense though. Now if somebody made one with a high cap mag, I'd buy it before the 5.7. I built a AK carbine for the 7.62x25 and using Romanian surplus I'm getting 1,925 fps out of a 16 inch barrel and thats with a 95 gr. bullet. Thats a lot of energy right there, I'd love to shoot some ballistic gel to see the wound channel.