If you aerate the water in a bucket first, it will gas off a lot quicker than just letting it sit for a day. The amount of chloramines left will stick around, but not enough to kill off the colonies of beneficial bacteria in organic soil or even aquariums.
I would for sure buy the RO unit though. Mostly so you yourself don't have to buy filtered water to drink anymore. I def won't drink straight tap water either.
I actually like having the chlorines/mines because I truck my plant/aquarium water in from town, so it stays sanitary in the capped off tanks & jugs until I use it. Also is a small boost to keeping all my hydroponic reservoirs sterile, without using much if any chlorine bleach or any additives. Free low PPM water and cheap dry nutes = constant partial daily water changes = decent concentration of chloramines= cold enough temps= less chance of root rot.