Like others have said, "Hot Loads" have a practical application. Using a real life example, there are a few 9mm 124gr +P loads on the market that mimic a .357 125gr magnum load... of course if you not loaded a .357 magnum load...

They have their purpose, but can also cause problems. Some weapons don't like them and can become unreliable, or worse, dangerous with hot loads. Recoil increases, decreasing accuracy in the inexperienced shooter. There can also be some also some legal implication when used for defence.

Personally I use Hornady 200gr +P .45ACP because my SIG P220 prefers this ammuntion over all the others I have tried.