Some manufacturers void your warranty if you fire steel cased ammo - CMMG specifically states such in their manuals. When I had my fancy but too heavy in the front Sig-Sauer 5.56mm rifle, an email query to their customer service also resulted in a reply stating that I ought not use steel cased ammo in it.

Some of the Wolf ammo used to smell horrible (the fumes made some people sick) when fired, especially indoors. Just something to be aware of.

A call to the maker of your handgun will determine whether or not they suggest the use of steel cased ammo, and what effect - if any - doing so will have on your warranty. The maker and their service techs will be the ones who fix and deal with broken guns, so their opinion as to steel cased ammo and their particular product probably are based on observation and not rumor and twice told tales. Shrug.