I used Red Sea Pro for a year and a half(No problems)
I switched to ESV because of all the hype,after 6 months, got tired of getting out the scale and mixing everything separate.
I went back to Red Sea but using the Blue Bucket because I like the lower parameters for my system as it is now.
I can litraly be ready for a water change in 10 min, Just add it to RODI,no scale,no waiting for each component to mix (faster that ESV)
I remember I was switching and trying top brand salts out there. From ESV, H2o, Salinity ect...... Only big difference was price. Than available was the next thing. Find a salt that is reasonable price and you can find or get easy. To me that's best advise. The money I on save on salt goes to other stuff. Bottom like pretty much all do same thing. Now using reef salt by seachem. Best thing DR Foster deliver it right to my door and free shipment.