The thing about 7.62x25 is that while it's not capable of shooting extremely light bullets at over 2000 fps like 5.7 can, it is much more powerful and it has the ability to shoot good hollow point bullets that will be effective and penetrate well, yet with a proper bullet would also be capable of defeating soft body armor to some extent. It would not do it as well as 5.7, but what 7.62x25 can do better than 5.7 is be a good stopper against an aggressor because the bullet is double the weight.
The 5.7 is just too light of a projectile and the spitzer bullet wouldn't do well with hollow points, nor do I think soft points would be moving fast enough to expand from a 5 inch barrel and the 5.7 was never intended to use those types of projectiles; it was built to NOT expand (Geneva Convention), beat body armor, and tumble in soft tissue to cause damage.
If you want a light weight bullet that moves very fast from a handgun that tumbles in soft tissue to do damage, then Inceptor 9mm+P is the answer and last I checked it was $8 cheaper a box and oh yeah, it's 9mm!
IMO, for the civilian shooter, 7.62x25 is the better choice, but for LE/Military 5.7 is better.