salts are just ph balanced, they are good at lower percentages for those with existing throat problems (like myself) who can't handle any throat hit, or those who use higher nicotine levels and want to decrease the throat hit caused by higher levels of nicotine.
If your happy with what TH you get, theres no cause to try it.. it's usually more expensive, so not much point if you dont need it for some reason.
I made a couple 8mg bottles of
juice for someone recently because I wasn't sure what percentage they used, and they freaked out at the utter lack of throat hit, even when subohming it.. but I design my
juice for exactly that purpose - no throat hit.