It really depends on the actual water quility. Best thing to do is get a sales rep test it. Culligan or the likes. That way you will know your hardness, iron level and or manganese.
I have a well - deep jet - that is new but has nasty water. Sulphur/iron at higher levels. Had Culligan come out and test - showed me what they had 'but' their systems would not do the job. And from tales told I wouldn't go for them.
Had a Kinetico rep come out and test - Sulphur/Iron at high levels. I went with Kinetico for various reasons.
1: Equipment uses no electricity
2: Have a dual tank system for treament
3: Regeneration rate is low - only 30 gallons (most systems use upto 100 gallons to regen.)
4: The sulphur system uses only household bleach - 1 gallon lasts about 3 months
5: Great 10 year warranty - and they stand behind it
I am not promoting them - just saying I have gone through it all and am very pleased with the results. Our water is clear and ordorless with no buildup on fixtures.