Iron in water is one of the main reasons for stains on clothing and plumbing fixtures and impacts taste of food and drinking water.
It is typically measured in PPM ( parts per million) Iron in water is classified into four categories 1. Ferrous (water soluble and clear) 2. Ferric (typically red in color and insoluble and instantly visible to human eye) 3. Bacterial and organically bound (insoluble) 4. Colloidal and inorganically bound ( typically yellow in color) Most softener's typically remove ferrous iron in water at moderate levels. Some go beyond this to remove other categories via additional filtration process or a whole house filter / carbon filter can be added prior to Softener to address some of these beyond ferrous iron removal.
Softener's would require you to factor in additional hardness for every 1 ppm of ferrous present in water i.e. when configuring the settings. I personally have not experienced lot of iron presence in Pleasanton water myself. If there is, it is mostly ferrous and but not other types of iron. As far as what model, make and type, my personal view is that any NSF / ANSI 44 or WQA ( water quality association) certified softener's should all perform alike given they all have to be compliant with same standards or have passed same standards during certification process.
At the end, if water, after softener is installed, is showing hardness level between 0-2 GPG, (grains per gallon) to me $700, 2k, 5k or 7k systems all mean the same i.e. doing the job of removing hardness ( calcium, magnesium and ferrous iron ) and as long as they are performing in that range. Like anything in life, it is a personal preference based on what one hears through marketing pitch, friends, how they ( softeners) look, what neighbors have etc. 😃
There are several $700-$900 NSF certified systems that come with very advanced control valves with good warranties, similarly brine and resin tank warranties up to 5/10 years. No matter what you choose, as long as it removes hardness ( intended purpose), just enjoy the softened water 😃 Go with person(s) / company who are local, knowledgeable in residential water purification, can assist you choose softener of your liking in a vendor neutral way and doesn't break the bank for install.