ALL water softeners are ion exchangers. Anyone is entitled to an opinion but physics don't care about opinions. It will not matter if you buy the cheapest or most expensive water softener.
I have two homes with water softeners. One came with a Pelican while I installed a home depot one in the other. Zero difference in how soft the water is or my interface with the machines.
https://www.homedepot.com/p/AQUASURE...48FM/311531700 here is a more compact one for 499.00
https://www.homedepot.com/p/Rheem-Pr...HS42/314448288