I really don't know the upkeep/maintenance pros and cons but I will say my kids will NOT swim in a saltwater pool. The last hotel we stayed at had one, and after 10 minutes they were whining that the water was stinging every little scratch on their body. I don't know if this is normal or if they had the salt solution too strong, but my kids can swim for HOURS so for them to get out of the pool after 10 minutes I know they were pretty miserable.
That is not normal. I have never heard of this. Salt water actually makes their skin feel good and no green hair or bleached out bathing suit and no stinging eyes. My next door neighbor's son had eczema and his Dr told him that our salt water pool was very good for it, and it actually cleared up his skin.