Pretty straightforward install, but takes up a little space. Took me about an hour and a half, start to finish. Not sure if it's common, but I'll get reimbursed for the cost because I live in third world America and the lead content of my water is high.
I'm not the OP, but the water quality in my parents town was so bad that they had to install a commercial reverse osmosis system in their basement. It holds like 600 gallons. Before they installed it, they would have to get new water fixtures every like 10 years and have a guy come in and descale the pipes in the house yearly. I think it was silicates.