That's what I do and it's a lot faster. I add conditioner to remove chlorine, chloramine and heavy metals so what's the deal--just curious.

Yeah, it used to be the case that leaving water to sit overnight was not only for bringing it up to room temperature but also for allowing the chlorine in tap water to evaporate out. These days most tap water also contains chloramines (which can't be removed by just sitting) and trace heavy metals - so water conditioners/dechlorinators are routinely used anyway - so yes from that point of view it's not as necessary. I guess it depends on how much water you need and whether you are going to be adding it at room temperature or heating it up to tank temperature before adding anyway. Also, personal preference too, some people just prefer to let tap water "age" before use - so if you have the space for that then that's fine too

I do it also because the hot water on my kitchen sink is broken. I have to heat water up in the microwave to wash dishes in. Alll I have is cold water so I have rust in my water too( building built in the 1928 and landlord just worked on the pipes so rust comes out) . I let it sit in buckets in the kitchen and treat it with prime then use it the next morning.