I use TSA-compatible locks (not Safe Skies) to have a modicum of additional security (more so that the bags' zippers don't open by themselves - against theft they are of dubious help).

Could use zip ties to the same effect, but I prefer something reusable.

As for making it easier to identify your bags, I think they are of no value here: you need something bigger; their conspicuousness is even lower than the additional security they provide.

Summing up: If you like them, go for them, but don't expect too much